Introduction
Ship Construction
Hull
Main Deck
Guard
Main
Deck Features
Bulwarks
Windlass
Hatches and Deck Openings
Cabin Sole
Plate
Rudder
Aft Cargo Hold and Lower Cargo
Deck
Engineering
Boiler
Engine
A-frame
Walking Beam and Connecting Rod
Paddle Shaft and Paddle Wheels
Architectural Window Glass
Production
Decoration
Glazing
Findings
Undecorated Glass
Colored Glass
Acid
Etched
Enameled/Etched Glass
Findings
Introduction
Natural processes and salvage attempts have stripped nearly every structural
feature rising above the main deck from the Maple Leaf. Very few disarticulated
timbers were found in the overburden and few if any can be traced to the
superstructure. The main deck is intact except for damage near the bow and
around the engineering spaces. The preserved portions of the vessel are the
lower hull, internal arrangements covered by the main deck, parts of the steam
power plant, and propulsion machinery. The following discussion is separated
into five parts. First is a discussion of the Maple Leaf's construction
including the wooden hull and other parts of the naval architecture. Second is a
presentation of the ship’s equipment and features found on the main deck. Third
is a brief discussion of the internal features found in the aft cargo hold.
Fourth is a presentation dealing with the remaining steam engine and the
mechanical drive train components. Last is a discussion of decorated and
undecorated architectural window glass.
Ship Construction
Hull
The registered dimensions of the Maple Leaf are length 173.2 feet from the inner
part of the stem to the fore part of the stern, beam 24.7 feet amidships and
depth of hold 10.6 feet (Certificate of Ownership). In the field, overall hull
length measured 184.6 feet from the front of the stem to the aft edge of the
stern counter; the beam was 24.8 feet for the hull itself and 44.3 feet across
the guards.
The hull is deeply buried so examination of structural components was generally
limited to those found at main deck level. However, a centerline keelson was
tentatively examined in 1994 through a hole in the lower cargo deck. It measured
12 inches sided and rose 25 inches above the ceiling planks.
At the bow, the stem rises 44 inches above the deck and has been badly damaged
at the top by toredo worms. It is molded 1 foot 6¼ inches and sided 1 foot 1¼
inches. A horizontal 1 inch wide rabbet is cut into both sides and the back of
the stem to create a ledge to support the bow cap rail. A wooden cutwater is
fastened to the stem’s forward edge with iron drift pins. The cutwater's sided
dimension is 9 ½ inches but the forward edge is so badly eroded precise
measurement of the molded dimension is impossible.
The bow was reinforced by at least one breast hook located under the deck
(Figure 17). Missing and damaged deck planking partially exposed the breast hook
but not enough to permit measurements. Additional reinforcement was provided by
two hawse pieces fitted to each side of the stem and attached to the breast hook
below. They extend aft 8 feet 3 inches along the bow at deck level. Each is
sided 13 inches, molded 11 inches and pierced by a fairlead and cast iron hawse
pipe. The tops of the hawse pieces are mortised to hold the bow cap rail
stanchions. The oval hawse pipes have an inside diameter of 7 ½ inches by 4
inches. The fairleads are located 2 feet 9 inches aft of the Fig 17 hawse pipes
and measure 1 foot 2 ½ inches by 5 ½ inches.
Most of the hull has standard double framing. There are triple frames and one
set of quadruple frames in the engineering space. This reinforcement appears
limited to the engineering space to support heavy machinery. Futtocks are molded
5 ½ inches with a sided dimension ranging between 4 and 8 inches. The average
sided dimension is 6 inches. Room and space dimensions varied depending on
double or triple framing configuration. Space averaged 11 inches while room
measured 13 inches for double frames and 16 to 19 inches for triple frames.
Fasteners used to hold the futtocks together were not observed.
All frame tops end at main deck level in an arrangement where each pair of
futtocks have staggered heights. This arrangement provides support for deck
beams at the side of the hull. Generally, one futtock is cut 7 inches lower so a
deck beam can rest on its top. The other futtock is cut even with the top of the
deck beam so the deck planking is level. Aft of the paddle box, deck beams rest
on top of the aft futtock. The arrangement was observed but not fully recorded
forward of the paddle box.
Deck beams are sided 5 ½ inches, molded 7 inches, and spaced 18 inches apart on
24 inch centers. Deck stanchions along the keelson provide the beams with
centerline support. One stanchion, removed for examination, was located at 137.5
feet on the baseline. It is 9 feet 2 ½ inches long. The lower half is square,
with a 5 inch square base, while the upper 4 feet 11 inches is round and machine
turned. The top fits into a rectangular mortise on the underside of a deck beam.
Stanchions were not found under every deck beam but no interval was determined.
The sheer strake is notched to allow deck beams to pass through the side of the
hull, extending to the guard beam on the sponson edge. This arrangement extended
the main deck to the maximum width of the paddle wheels and created the
characteristic sponson hull. Notches in the sheer strake get progressively
deeper moving aft along the hull. From 1 inch forward of the paddle wheel to 7
inches aft of the wheel. All deck beams examined on the starboard side have
broken at the side of the hull.
In addition to the support provided by the futtocks, the beams rest on top of a
large shelf clamp inside the hull. The shelf clamp is 5 inches molded and 27
inches sided. It is made of two thick planks, one on top of the other, measuring
12 and 15 inches wide respectively. Ceiling planks on the interior are 2 ½
inches molded and butt against the lower edge of the clamp. Outer hull planks
measured 2 to 2 ½ inches thick but width and fastening patterns were not
recorded.
The knee pattern observed inside and outside the hull further supports deck
beams as well as providing longitudinal stiffening to the hull. A hanging knee
was observed under a deck beam on the exterior hull just aft of the starboard
paddle wheel. This may indicate each deck beam is supported by a similar hanging
knee.
Dagger knees are fastened to every other deck beam inside the hull (Figure 18).
Their pattern suggests they are part of the longitudinal reinforcing system.
Forward of the paddle box, the top of the dagger knee leans aft and fastens to
the forward side of the deck beam. The lower leg of the knee butts up under the
adjacent deck beam. Aft of the paddle box, the pattern is reversed so the knees
angle forward. One disarticulated dagger knee examined on the surface was 4 ½
inches wide, 27 inches long on the beveled top fig 18 edge and 41 ½ inches long
on the lower portion. Square headed iron bolts, 1 inch in diameter, were used to
fasten the knee to the ship; two on the deck beam and three on the shelf clamp.
Four hanging knees are located amidships in front of the boiler. Damage to the
engine room caused by demolition destroyed the deck, deck beams, and many knees
in this area. The remaining hanging knees are spaced on 24 inch centers. There
is a gap between this group of hanging knees and the dagger knees located
forward making it impossible to determine exactly where the kneeing pattern
changed.
Main Deck
As the Maple Leaf's superstructure disintegrated, the main deck became the top
surface of the site. Deck planks measure 2 ½ inches thick and average 6 inches
wide. They are fastened to deck beams with two iron spikes placed in a diagonal
pattern. Each ¼ inch square spike is set in a counter sunk hole and capped with
a wooden bung. Although the deck was built for strength and much of it is
intact, several areas of extensive damage have ruined the deck's original
structural integrity. Only the sediment filling the interior spaces keeps the
deck from collapsing.
The forward deck is extensively damaged along the starboard side approximately
15 feet aft of the bow (Figure 14). This area roughly corresponds to the main
impact of the torpedo explosion concentrated on the starboard side, about thirty
feet from the stem. Reportedly, "the hog frame was broken and the whole side of
the vessel was stove in" (Farnham 1864).
Another damaged area is located between the forecastle hatch and the forward
cargo hatch. Deck planking has been stripped off and several deck beams are
broken. Barnacles growing on material recovered from the hold indicate planking
was removed before the vessel filled with sediment.
The largest damaged area is over the engineering spaces. Between 70 feet and 105
feet on the baseline, much of the deck is missing or severely damaged (Figure
15). The open space is littered with broken timbers, including the forward
paddle beam, and the starboard boiler lay exposed. Damage continues aft of the
paddle shaft to approximately 120 feet on the baseline. The aft paddle beam and
many deck beams are broken while some planking is loose or missing. This
destruction probably occurred in 1883 when Ross removed the crank frame and
gallows frame, and allowed the walking beam to fall through the deck causing
severe damage along the ship's centerline
Aft of 120 feet, the main deck is intact to the stern. The hole cut through the
deck in 1988 to gain access to the aft cargo hold is centered at 139 feet on the
baseline. It begins on the centerline and extends to the port side, measuring
approximately 8 feet athwart ship and 42 inches bow to stern. It is covered with
an aluminum frame and Plexiglas panels.
Guard
The longitudinal sponson hull is a distinguishing characteristic on nineteenth
century eastern North American steamboats. The structure is an evolutionary
development that started as a box frame extending from each side of the ship to
house the paddle wheels and support the ends of the paddle shaft. Eventually the
frame’s outer edge was lengthened fore and aft and tapered inboard to meet the
stem and stern. The overhanging sponson, or guard, often added twenty feet or
more to the vessel's main deck beam depending on the width of the paddle wheels
(Cuthbertson 1931:243-244; Russell 1861:108,113).
On the Maple Leaf, the frame can be viewed as a massive structure that overlies
the hull. The fore and aft ends are composed of two paddle beams while the sides
are framed by the guard beams. The hull passes through the middle of the frame
and also forms the interior side of each paddle wheel opening. The guard beam is
9 inches molded and 12 inches sided aft of the paddle wheel. A wooden rub rail
is fastened to the exterior side. The aft paddle beam is made of two timbers
fastened together one in front of the other. The larger forward timber, 16
inches sided and 10 inches molded, extends completely across the vessel to both
guard beams. The smaller timber, sided 8 inches and molded 10 inches, ends
inside the hull and rests on the shelf clamp. Hanging knees on the interior and
exterior support the large beam as it passes through the hull. The exterior knee
is extremely large. The top extends horizontally from the hull to the guard
beam.
Wooden trusses built on the outer edge of the guards supported the ends of the
iron paddle wheel shaft. The starboard truss was built as a symmetrical A-frame
(Figure 19). It rises approximately 6 feet above main deck level on timber legs
measuring 10 ½ inches high and 8 ½ inches wide. The top is 6 feet 8 inches long
and 13¼ inches wide. A large square notch centered in the top, 34 inches long
and 5 ½ inches deep, once held a pillow block to secure the end of the paddle
shaft. The pillow block is no longer present fig 19 and the paddle shaft has
been dislodged from its original position. The port pillow block is still in
place on the port side shaft support and is discussed below with the paddle
shaft. The ship’s main deck is expanded over the entire guard by extending the
deck beams out of the hull to the guard beam. Deck construction is identical to
the rest of the main deck. Planks measure 2 ½ inches thick, average 6 inches
wide, and are fastened in a diagonal pattern.
Figure 16 shows a narrow opening,
22 inches wide, behind the paddle beam just before the deck planking begins. The
purpose of this opening is not clear but it may represent a way for water picked
up by the paddle wheel to drain out of the paddle box.
Most of the starboard guard was examined except the forward end. It extends a
maximum of 9.6 feet from the side of the hull to the outer edge at the paddle
wheel. The rectangular paddle wheel opening in the guard is located amidships,
centered 102 feet from the stem. It extends from 86 feet to 118 feet aft of the
stem with an overall length of 32 feet. The inside width of the opening is 8
feet 6 inches.
The guard's general condition is very good and most of the deck planking is
still intact. However, those deck beams that once extended from the side of the
ship to support the guard have all broken where they pass through the hull. As a
result, the guard sags at a 10 to 15 degree angle (Figure 20). Also, late
nineteenth century demolition caused a fragment of the walking beam to fall on
the aft paddle beam, breaking a section out of the center. The beam is also
broken at the edge of the hull.
Hogging Truss fig 20 Portions of the hogging truss found on the starboard side
represent one major element of the longitudinal reinforcing system. One of two
built into the ship, the truss's overall length was 131 feet extending from 24
feet to 155 feet aft of the stem. Although both lower ends of the truss are
present, the upper portion is missing. In discussing the Maple Leaf's loss,
Second Officer Charles Farnham stated the explosion broke one of the hogging
trusses (Farnham 1864). Additional damage probably resulted when Roderick Ross
cleared wreckage for safe navigation. Inclement weather and bad visibility made
detailed recording of the truss’s forward end impossible. The aft truss section
came loose as supporting sediment was removed. It was subsequently recovered for
documentation (Figure 21).
The aft truss segment is built on a sole timber, or base, which measures 10 ½
inches wide by 10 inches high and 17 feet long. It is badly eroded. The sole
timber was fastened over the frame tops at the top of the hull. The bottom has
notches to fit over frame tops and deck beams as they pass through the hull.
Iron drift pins fastened the sole timber to the shelf clamp and deck planking
butts against the side. Wooden chocks fitted between the deck beams and resting
on the shelf clamp distribute the weight of the truss more evenly. One of these
chocks is still fastened to the bottom of the sole timber by a drift pin.
Several similar blocks of wood were found unsecured in the space between the
deck beams.
The arching chord timber is joined to the sole timber with scarphs and iron
drift pins. The attachment is strengthened on top by a large knee and below by a
small wooden chock located under the chord. The chord fragment measures 8½
inches wide by fig 21 12 inches high. Originally, the chord was composed of many
segments joined together to form an arch. A notch measuring 3 inches wide and 50
inches long on the upper end of the fragment is the mortise joint used to attach
the next section of the arch. The mortise is filled by a tenon fragment from the
next chord section.
The Maple Leaf presumably had a transverse support system to keep the guards
from sagging and the trusses from swaying. The system probably used horizontal
tie rods running between the top of each hogging truss with diagonal rods
linking the trusses to the outer edge of the guard. Using turnbuckles on the tie
rods to create tension, the system would stiffen the vessel transversely. A
short tie rod, measuring 4 feet long and 1 ½ inches in diameter, is attached to
an eye bolt on the paddle beam and is probably the diagonal rod linking the
guard to the hogging truss. A broken turn buckle is fastened to the end of the
rod. Another section of rod laying on the deck nearby may also be part of this
system. One end is attached to an eye on a metal plate that bolted the rod to a
timber, possibly the hogging truss (Bates 1968:23).
Main Deck Features
Bulwarks
A low bulwark remains intact along the aft starboard guard extending from the
paddle wheel to the stern. Originally, this structure stood 32 inches high and
marked the edge of an exterior walkway providing access to cabins on the aft
main deck. A similar bulwark was not found forward of the paddle wheel with the
exception of a cap rail at the bow.
The aft bulwark is intact except for damage incurred by natural deterioration
and possibly by demolition of the superstructure. The facing planks nailed to
the bulwark stanchions are falling off as the iron fasteners corrode. Most of
the starboard cap rail has been pulled off and now lays in the mud above the
deck. The cap rail at the stern and parts of the bulwark were removed by SJAEI
in 1991.
The bulwark is constructed with stanchions planked on both sides and topped with
a cap rail (Figure 22). Stanchions are fitted through the waterway into the edge
of the guard with an average spacing of 36 inches. Each stanchion is roughly
32.5 inches tall, 3 ½ inches square at the base, tapering slightly towards the
top. A tenon at the top of the stanchion fits into a mortise on the underside of
the cap rail. The assembly is secured by a ½ inch diameter iron drift pin driven
through the joint at an angle. The cap rail is 6 inches wide and 1½ inches
thick. The underside is grooved along the outboard edge to accept horizontal
planking used to panel the exterior side of the bulwark. Horizontal tongue and
groove planking, 4⅞ inches wide and ½ inch thick, covers both sides of the
bulwark. The top of the cap rail is mortised to accept stiles that helped
support the upper deck. Although no stiles were found, mortises in the cap rail
indicate they were placed at irregular intervals, more than 36 inches apart.
One wooden fairlead is located in the bulwark, at 155 feet on the baseline. It
is made from a solid block of wood measuring 43¾ inches wide, 10 inches high and
8 inches thick. The oval opening through the center is 17 inches wide and 4
inches high.
A gangway opening to board the ship is located in the bulwark just aft of the
paddle wheel (Figure 16). Originally the 55 inch wide opening was framed by a
fig 22 stanchion post on each side. The forward stanchion is missing but its
location is marked by a mortise in the waterway. The aft stanchion is standing
but the top is eroded off 70 inches above the deck. The lower portion of the
stanchion is rectangular, measuring 6 by 3 inches, with a rabbet on one corner.
This appears to be a stop for the gate, or door, used to close the gangway
opening. The rectangular section rises 36 inches above deck, indicating the
height of the door, and becomes round for the rest of its length.
The cap rail found at the bow in 1989 was removed for conservation and display
at the Jacksonville Museum of Science and History. Documentation of this piece
took place at the museum (Figure 23). The V-shaped structure is composed of two
cap rails fastened together at the apex by a horizontal lodging knee. This
configuration forms a square mortise that fits around the stem and rests on a
narrow 1 inch wide ledge cut into the stem. Each arm of the V is a rail
constructed of two timbers laid on top of each other and fastened together with
iron bolts secured on the underside with square nuts. Crude chocks are cut into
the top timber of each rail. Damage by wood boring mollusks is evident on the
forward ends of each rail (Cantelas 1992).
Windlass
The windlass is located 8 feet aft of the stem and is the largest feature on the
forward deck (Figure 24). The wooden barrel is mounted on two carrick bitts held
in place by cheeks and braced forward by large knees. A strongback made of 1
inch diameter iron rod braced the carrick bitts laterally against each other but
is now broken. The pawl post is located just forward of the windlass and rises 5
feet 2 3/4 inches above fig 23 fig 24 the deck. This massive timber measures 18
inches square and is likely stepped into the bow deadwood (Chapelle 1973:602).
The pawl, a ratchet used to stop the windlass from turning in reverse, is
missing from the aft face of the pawl post (Paasch 1908:121-122). The windlass
operated manually by inserting hand spikes into square holes along the barrel
and turning the barrel by hand.
The windlass provided lifting power for a number of tasks but its primary
purpose was to raise the anchors carried at the bow. As anchor chain was brought
aboard it passed over the windlass barrel and through the deck into the chain
locker below. Normally, anchor chain passed through the deck by way of an iron
chain pipe. Chain pipes are absent on the Maple Leaf and no other openings were
noted near the windlass. However, two unusually wide deck planks located just
aft of the windlass whelps may have been removable to provide access to a chain
locker below.
Hatches and Deck Openings
Four hatches are located on the main deck. These allowed entry to the forecastle
cabin, two cargo holds, and the engine room. The forecastle hatch is a small
opening 23 feet 7 inches aft of the stem which provides passage to the
forecastle cabin. The opening measures 4 feet athwart ship and 2 feet 3 ½ inches
fore and aft. The coaming rises 6 inches above the deck and is 4¼ inches wide.
The 1856 Maple Leaf ambrotype shows a small square structure on the weather deck
in the area of this hatch that probably covered a companionway leading from the
upper deck to the forecastle (Figure 25). Just aft of the forecastle hatch on
the starboard side is a 6 inch circular hole passing through the deck. Fig 25
The edge is cleanly cut with no sign of wear and no evidence of a deck fitting
mounted to the hole.
The badly damaged forward cargo hatch is located 43 feet 10 inches aft of the
stem. Three sides of the coaming remained in place and the missing aft coaming
was found on the deck a short distance away. The deck beam supporting the
forward coaming is broken at the hatch. Originally, the opening measured 3 feet
7 inches athwart ship and 3 feet 7 inches fore and aft.
Part of the hatch was temporarily recovered to examine construction details
(Figure 26). The same type of general construction methods are used on all the
vessel's hatches. First, a section of one deck beam is removed along the ship's
centerline to create a large opening. Carlings placed along the side of the
opening support the cut ends of the deck beam. Next, the timbers forming the
hatch are secured in place. Coaming timbers rest on top of the carlings along
the side of the opening and head ledge timbers sit on deck beams at each end.
The component timbers are joined at the corners with a lapped rabbet joint and
fastened to the underlying deck beams and carlings with iron drift pins. Each
coaming has three mortises on the interior face to fit strongback timbers that
supported the hatch cover.
A large hatch used to enter the engine room is located 64.5 feet aft of the stem
(Figure 15). The opening measures 5 feet fore and aft and 6 feet athwart ship.
It was used to load wood into the bunkers to fuel the boilers when the vessel
operated on the Great Lakes. The wood coaming is badly worn from loading fuel
despite a metal strap placed around the top edge for protection. Two deck beams
are sistered together on the fig 26 forward side of the hatch and may represent
a repair or reinforcement. The forward beam continues across the ship,
supporting the forward hatch coaming, while the aft beam is cut short and butts
against the side of the hatch. Beams forward and aft of the pair still retain
the normal 18 inch spacing typical for this vessel.
A large circular cast iron through-deck fitting is located on the starboard side
of the engine room hatch. The interior diameter is 1.3 feet. This appears to be
part of the engine room ventilator system. The 1856 ambrotype shows a large
ventilator funnel over the engine spaces on the starboard side.
Remains of the aft cargo hatch were found approximately 115 feet on the
baseline. This area was badly damaged when the walking beam crashed through the
deck during demolition work in 1883 (Figure 16). Only one disarticulated hatch coaming was found in the damaged area. It is 32 inches long and notched to
accept three strong backs. The hatch was located between the crank frame timbers
just forward of the paddle beam.
A bulkhead below the main deck, at 116 feet, separates the aft cargo hold from
the engine room. The bulkhead stops on each side at the crank frame timbers
creating a gap in the center. The location of the bulkhead further suggests the
hatch location between the crank frame timbers at the forward end of the cargo
hold.
Two small through deck openings were found on the aft deck. A small circular
hole is located 141 feet aft and 8 feet starboard of the centerline. The 6 inch
diameter hole has a cleanly cut edge with no sign of wear and no evidence of a
deck fitting mounted through. A sandstone through-deck fitting is positioned at
165 feet on the baseline and 1.5 feet to starboard. The fitting is flush to the
deck, 18 inches square with a 7 inch diameter hole through the center. The
purpose of this feature is not known. The use of stone suggests it may have
insulated the wooden deck from a hot steam or water pipe used to heat the upper
cabins.
Cabin Sole Plate
Evidence of the superstructure and cabins is nearly absent over most of the
site. However, on the aft deck several cabin sole plates were located, marking
the position of cabin walls. Figure 16 shows their locations. Two different
types of plates are present. Both are roughly 2 inches high by 4 inches wide
fastened to the deck with nails. One type is a plain unmodified rectangular
board. The other type has a concave surface on each side.
Except for one curving plate near the stern, all plates lie on the ship's
longitudinal axis. Both interior and exterior walls appear to be represented.
The curving plate at the stern is an exterior wall and demonstrates the shape of
the after most cabin. The straight plate branching off near the starboard end is
an interior wall. Another short segment of plate near the starboard side at 160
feet on the baseline is probably for an exterior wall and is notched to accept
wall studs on 24 inch centers. A 12.5 foot long section of unmodified plate is
located near the forward end of the aft deck. It is 8 feet starboard of the
ship's centerline suggesting it is an interior wall.
Rudder
The rudder is still attached to the wreck indicated by the rudder post passing
through the deck near the stern. The post is 1 foot in diameter and broken off
7.2 feet above the deck. It rose through the saloon deck above, and was probably
rigged with emergency steering tackle.
On the main deck, two short, wide boards fit around the rudder post. The purpose
of the boards is unknown but removing them may provide access to steering gear
below deck. Aft of the rudder a small rectangular wooden block is attached to
the two planks. It has a shallow rectangular mortise in the top but its function
is unknown.
Aft Cargo Hold and Lower Cargo Deck
The internal architecture of the aft hold appears undamaged. However, the small
area open for examination, centered 139 feet aft of the stem, allowed only a
tentative description of interior construction. The deck and deck beams covering
the aft cargo hold are intact but have suffered severe structural damage. All
deck beams observed in the confined space are broken approximately 3 feet from
the port side causing the central portion of the deck to sag 2.5 feet at the
break. Removing sediment from the cargo space during excavation may have caused
the sag to increase.
The main feature inside the hold is the lower cargo deck built approximately 4
feet above the bilge ceiling and 2 feet above the keelson (Figure 27). The cargo
is packed on this lower deck. The deck is lightly built and planked with tongue
and groove boards 4¼ inches wide and⅞ inch thick laid longitudinally. The
planking is nailed to 2 by 3 inch deck beams spaced on 24 inch centers. Short
centerline deck stanchions, resting on the keelson, support the beams. Each
stanchion is rabbeted on the ends to fit around the fig 27 corners of the
keelson and deck beams. These precarious joints are secured with a few small
nails. The lower deck construction on the Maple Leaf’s is almost identical to
the steamboat Commonwealth (Figure 28).
Main deck stanchions pass through the lower deck and are mortised to main deck
beams. The lower deck planks are fitted around the stanchions and not attached.
One stanchion recovered for examination exhibited rope wear marks, presumably
caused by securing or moving cargo in the hold.
Engineering
Typical of side wheel steamers, the Maple Leaf's engine room is located
amidships between the paddle wheels. Evidence from the site indicates the
A-frame that supported the walking beam was located forward of the paddle shaft.
It follows that the engine, including the condenser, air pump, and hot well, was
placed in front of the A-frame. A boiler is located on each side of the A-frame
and extended aft under the paddle shaft. Fuel bunkers are probably forward near
the engineering hatch along the side of the hull. For reference in the following
discussion, Figure 29 illustrates the general configuration of a marine walking
beam engine.
The 1993 investigation in the engineering spaces located one boiler, the paddle
shaft, the paddle shaft connecting rod and walking beam fragment, A-frame
timbers, and fragments of the air pump. The engine is missing, including the
engine cylinder, condenser, hot well, and valve chest. Timbers and other debris
fill all open spaces of the engine room restricting access to lower areas. This
material was left in place limiting fig 28 fig 29 documentation to the upper
levels of the engine spaces. Each major component will be discussed separately.
Boiler
Historical records and the 1856 ambrotype indicate the Maple Leaf had two
cylindrical boilers placed on either side of the A-frame (Figure 25). These
boilers were new when installed at the Kingston Marine Railway Yard in 1851, and
repaired in Toronto in 1858 (DBW March 26, 1851; Girvin 1993:89). Although only
the starboard boiler was examined, the port boiler is considered to be identical
in design. The 7 foot diameter starboard boiler begins at 86.5 feet on the
baseline. The aft end of the port boiler was found at 114 feet on the baseline,
indicating both boilers are 27.5 feet long and pass under the paddle shaft. They
are return, fire tube boilers with the firebox facing forward.
The remains of the starboard boiler smoke stack are 2.5 feet in diameter and
centered 6 feet aft of the boiler face. The stack is encircled by a steam dome
on top of the boiler. The steam dome is badly damaged suggesting it may have
suffered an explosion. Shredded metal plating flares out away from the dome's
center indicating a strong outward blast. This blast probably caused the boiler
face to separate and lean forward, creating a 5 inch gap. The fire box doors on
the boiler face were found open, offering further evidence of an explosion.
The starboard boiler is badly corroded and large debris fills the open space in
front. These obstacles limited examination to the upper port side of the boiler
face. Figure 30 is a reconstruction of the face combining data gathered in the
field with historical information on similar boilers. Dashed lines on the
starboard side and lower portions are a hypothetical reconstruction.
A glass water gauge and four gauge cocks, on the upper right side of the face,
indicated water level in the boiler. Water level had to be maintained above the
fire tubes while the boiler operated. Otherwise, fresh feed water touching the
hot tubes flashed into steam, dramatically increasing boiler pressure and
possibly causing an explosion (Ward 1860:23).
The Maple Leaf's glass water gauge is a ball float type designed with a lower
vertical pressure chamber and an upper sight glass (Figure 31). The pressure
chamber is open to the boiler at the top and bottom through short brass
fittings, allowing boiler water to maintain an equal height in both vessels.
Inside the pressure chamber, a hollow brass ball floats on the water surface. A
brass wire soldered to the ball passes through a leather gasket at the top of
the pressure chamber into a thick sight glass tube. Water level in the boiler is
indicated by the wire height on a scale mounted behind the sight glass. The
thick glass tube is mounted in a brass holder and held in place by screw
tension. A scale mounted on the holder, behind the tube, is marked in one inch
increments beginning with one on the bottom and nine on top. A cock on the
bottom of the pressure chamber drained excess water.
Many nineteenth century glass water gauges omit the pressure chamber completely.
The sight glass is directly connected to the boiler at the top and bottom by
metal fittings. For safety, these fittings have stop cocks to turn off pressure
to the sight fig 30 fig 31 glass if it breaks (Lardner 1848:116). The Maple
Leaf's glass water gauge does not have stop cocks to isolate the pressure
chamber. It is only open to the atmosphere at the top, through the sight glass.
The pressure chamber is designed to seal itself if the glass breaks. The solder
holding the wire to the brass ball float is shaped to fit a conical depression
at the top of the pressure chamber. If the glass broke, boiler pressure forced
the brass ball against the top of the pressure chamber causing the solder to
seal the opening.
While a glass water gauge gave an accurate measure of water level, it was prone
to fouling and breakage. Gauge cocks provided a reliable method of checking
water level with slightly less accuracy (Figure 32). Four brass gauge cocks were
mounted diagonally on the port side of the glass water gauge. The top and bottom
cocks are 8½ inches apart vertically and align horizontally with the top and
bottom openings on the water gauge's pressure chamber.
Placement of the cocks indicates the highest and lowest water levels allowable
to permit safe boiler operation. "The highest cock is at a point above which the
water cannot be permitted to rise without encroaching upon the room provided as
a reservoir for steam; and the lowest cock is at a point below which the water
cannot be permitted to fall, without endangering exposure of the flues" (Ward
1860:23). The two intermediate cocks show water between high and low levels. In
operation, if one of these cocks is opened and emits steam, water level is below
that point. If the cock emits water, water level is above that point (Ward
1860:23). The gauge cock shown in Figure 32 is in the closed position. Fig 32
Large debris hindered investigation of the boiler face below the gauge cocks.
Except for the port side fire door, much of the lower area could only be
examined by feeling around the debris. Openings for two fire doors are spaced 28
inches apart. Each door hinged outward away from the center of the boiler and
was fully open when examined. A heat baffle on the inside of the port door
indicates the fire box opening measured 16 by 12 inches. Mud filled the fire box
so the interior was not examined.
An opening detected 30 inches below the fire door is probably an open ash door.
Obstacles made further examination impossible. The overall height of the fire
box was not measured because the bottom of the fire box could not be found.
Engine
The field investigation did not locate any intact components of the engine
suggesting it was removed or destroyed. Unfortunately, historical sources only
provide a brief description. The piston had an 11 foot stroke and a diameter of
52 inches (Heyl 1967:171). The stroke length is verified by the crank which
measures 5.5 feet between the centers of the crank pin and paddle shaft.
Pieces of the engine were found in a deep excavation located in the center of
the ship, 87 feet from the stem. The excavation uncovered two cast iron cylinder
fragments eight feet below the baseline. One fragment was removed for
conservation and analysis. This fragment is part of the air pump cylinder and
includes a flange and brass compression ring. The compression ring indicates the
fragment is from the top or bottom of the cylinder. It attached either to the
bed plate at the base or to the hot well at the top. The cylinder diameter was
approximately 24¼ inches and wall thickness 1 inch. Deep vertical striations
mark the interior of the cylinder wall. These striations pass through an
unidentified filler metal used to fill small voids and imperfections in the cast
iron. This indicates the striations occurred during use. They apparently
resulted when particles in the water pumped from the condenser became trapped
between the piston and cylinder wall.
A-frame
Located on the ship’s centerline, the A-frame, or gallows frame, functioned to
support the walking beam, linking the engine to the paddle shaft. It also
incorporated the crank frame to support the paddle shaft. On the Maple Leaf, the
massive structure was composed of large wooden timbers held together with a
complex system of iron tie rods. It was removed by Roderick Ross in 1883.
Many twisted and broken tie rods lie between the paddle shaft and the front of
the boiler to mark the A-frame's position. One timber forming the forward
starboard leg is located in front of the boiler and measures 16 by 12 inches in
cross section. It is broken off below the river bottom and slopes down towards
the bow.
Two timbers mark the crank frame at 114.8 feet on the baseline, just behind the
boilers. They measure 9 by 14 inches and are spaced 6.7 feet apart. The tops are
sawn or broken off flat just below the river bottom mud line. Both timbers pass
aft of the bulkhead separating the engine room from the aft cargo hold. They
slope down into the hold, towards the stern, at a 45 degree angle.
Walking Beam and Connecting Rod
A cast iron walking beam, pivoting on trunnions atop the A-frame, transferred
power from the engine to the paddle shaft. The piston rod imparted a
reciprocating, or up and down, motion to the forward end of the beam. This
motion was transferred to the paddle shaft connecting rod on the aft end of the
beam, which in turn rotated the cranks on the paddle shaft. This rotary motion
caused the paddle wheels to turn.
A fragment of the walking beam is connected to the paddle shaft connecting rod
and paddle cranks (Figure 33). Apparently, Ross's demolition caused the beam to
break and fall aft, pivoting on the crank pin, carrying the connecting rod with
it and smashing through the main deck. Now, the connecting rod rests
horizontally and the walking beam fragment hangs vertically below it. The
fragment is 8.7 feet long.
The walking beam is solid cast iron and had a long, narrow elliptical shape.
Cross section views of the beam in Figure 33 show a center web with a flange
around the circumference and another longitudinally down the center. The flange
stiffens and strengthens the central web. A wrought iron band placed around the
circumference of the beam provided additional strength and reinforcement. The
band has been removed but four U-shaped wrought iron band guides are cast into
the beam to hold the band in place. They are paired on opposite sides of the
beam.
Two pins on the beam fragment are attachment points for connecting rods. These
pins are centered 7.2 feet apart. The small pin near the broken end of the beam
powered auxiliary equipment, possibly a boiler feed water pump. The connecting
rod strap has been dismantled and the rod removed leaving the 2½ inch diameter
pin intact. fig 33 The second pin attaches the large paddle shaft connecting rod
to the end of the walking beam. This pin is 5 inches in diameter and flares on
the end to hold the bearing blocks in place. The journal assembly connecting the
rod and the beam is intact on the starboard side but has been taken apart on the
port side. Apparently, there was an unsuccessful attempt to disconnect the rod
before the beam was broken and fell into the river.
The intact journal on the starboard side is a typical nineteenth century
example. The connecting rod forms a yoke to meet the pin extending from each
side of the walking beam. On both sides of the walking beam a two piece brass
bearing fits over the end of the pin and rests on top of the yoke. Next, a pin
strap fits over the pin and bearing. Slots on each end of the strap align with a
slot in the connecting rod below the bearing. The assembly is secured by a
placing a tapered key and gib through the aligned slots. A locking bolt holds
the key in place. An oiling cup, normally found on top of the journal to
lubricate the bearing, is missing.
The paddle shaft connecting rod is wrought iron and lies on the centerline of
the ship approximately 3 feet below the river bottom. It measures 18 feet 5
inches between the crank pin and the walking beam pin and is 6 inches in
diameter. On the lower end, the rod is still connected to the crank pin which is
7¼ inches in diameter. The rod is fastened to the crank pin with a strap in the
same fashion it is attached to the walking beam.
Paddle Shaft and Paddle Wheels
The paddle shaft is located slightly aft of amidships and is the largest feature
on the site regularly exposed above the river bottom. The structure is actually
two shafts, one on the port and one on the starboard side, joined in the middle
by two cranks and a crank pin. The baseline passes through the cranks at 102
feet. These three sections will be dealt with separately.
Each wrought iron crank was attached to the paddle shafts by heating and
shrinking over the ends of the shafts (Ward 1861:105). The overall length of
each crank measured 6 feet 10 inches with a maximum thickness of 11 inches. The
distance between the center of the paddle shaft and the crank pin center is 5
feet 6 inches, indicating a piston stroke of 11 feet. This stroke length
confirms historical documentation (Heyl 1967:171).
The cranks were originally connected together by a crank pin. However, Ross’s
demolition work pulled the starboard crank off the crank pin. The crank pin is
normally attached to only one crank and rides free in the other. This
arrangement is called a drag link and allows the paddle shaft to shift as the
guards settle without straining the cranks (Ward 1860:105-106). On the Maple
Leaf, the crank pin attached to the port crank is 7¼ inches in diameter.
On the port side paddle shaft two narrow straps encircle the shaft adjacent to
the crank and probably mark the location of one pillow block mount. The straps
are 1½ inches wide and are spaced 12 inches apart. This is the only feature
noted on the port shaft.
Port side shaft diameter decreases in stages from the cranks to the outboard
end. The shaft diameter is 11 inches between the cranks and paddle wheel flange.
Diameter between the flanges is 10 inches and further reduces to 8 inches on the
outboard side. The end of the shaft secured by the outside pillow block is 7
inches in diameter. In 1883, Ross's workers removed the pillow blocks holding
the two shafts in place and moved them from their mountings (Russell 1883). They
pushed the starboard end well aft while the port shaft shifted only slightly aft
of its original alignment. The outside pillow block remains on the port guard
but all others are missing. It contains a two piece brass bearing to fit the end
of the 7 inch diameter paddle shaft.
The port shaft is broken 14 feet from the crank, near the outboard end. The
short broken section is 5 feet 10¾ inches long and located slightly aft of the
main shaft. This piece carried the radial paddle wheel and includes two paddle
wheel flanges, spaced 30 inches apart, with wooden paddle arms. The upper
portion of both flanges are broken off along with the paddle arms. The lower
half, with paddle arms attached, projects into the bottom.
The starboard shaft is complete and undamaged despite being pushed aft on the
outboard end. This shaft is actually two pieces joined by a large coupling
located 4 feet from the crank (Figure 15). The coupling consists of two flanges
that fit over the end of each shaft segment. They butt together and are fastened
around the perimeter by large bolts. The Maple Leaf broke its paddle shaft
shortly after leaving the port of Charlotte, New York on July 16, 1859. The
local Rochester, New York newspaper mentions the installation of a new shaft
(Union and Advertiser July 16, August 1, 1859). It seems instead, the old shaft
was fixed or a new section added with the use of the coupling. Both the port and
starboard shafts were manufactured at the same time by the Kingston Foundry when
the Maple Leaf was built. The port shaft was forged as one section indicating
the starboard shaft was also originally one piece. The coupling is evidence of
repair work.
Two eccentric bands hanging loose from the starboard paddle shaft on each side
of the coupling are the only remaining parts of the engine valve gear. They are
badly bent and the eccentric arms are broken off. Their condition made it
impossible to determine the throw, or horizontal distance, traveled by the
eccentrics. Each band is slightly different in size, possibly due to corrosion
or concretion formation. The outboard band is 1¾ inches wide and 1¼ inches
thick. The inboard band is 2 inches wide and 1 inch thick. No eccentrics or
eccentric bands were found on the port paddle shaft.
Two cast iron paddle wheel flanges are attached near the end of the shaft to
hold the paddle arms of the starboard wheel. They are spaced 50½ inches apart on
center. The inside flange is broken in half leaving the lower portion in place
with paddle arms still attached. The lower ends of all the arms are deeply
embedded in the bottom. The outside flange is extensively damaged. All of the
perimeter has been broken away along with the paddle arms, leaving only the
central hub.
Comparing the spacing between the flanges on the port and starboard sides
reveals a large discrepancy. Spacing on the port flanges is 30 inches and on the
starboard flanges 50½ inches. The difference in spacing is due to damage
incurred during demolition work. All flanges are badly damaged and appear to
have shifted on the paddle shaft.
The Maple Leaf had simple radial paddle wheels. The intact lower portions of
both paddle wheels were inaccessible. However, disarticulated fragments found
during excavation allow a hypothetical reconstruction of the port paddle wheel
(Figures 34 and 35).
Originally, the cast iron flanges were 6 feet in diameter with 24 arm pockets to
hold the paddle arms. The method used to attach the flanges to the shaft was not
determined. Two paddle arms and a bucket were examined on the port side aft of
the shaft. The 3 by 7 inch arms, or spokes, are broken off the flange but had an
overall length of approximately 14 feet. The proximal ends are tapered to fit
the arm pockets on the flange and are attached with two bolts. Notches on the
distal ends of the arms probably held a stiffening or reinforcing band around
the circumference of the wheel. Two additional reinforcing straps once circled
the wheel as indicated by iron strap fragments and fasteners on the paddle arms.
Although some sort of cross bracing certainly existed between the paddle arms to
provide transverse stiffening, no evidence of this bracing was found.
The paddle bucket attached to the end of the paddle arms. One badly eroded
bucket recovered for examination measured roughly 5 feet 2 inches across the
blade and 18 inches wide. It is made from two planks attached to the paddle arms
by iron fasteners. The fasteners were missing but the holes measured 1 inch in
diameter. The fasteners indicate the paddle arms were attached near each side of
the bucket and spaced 52 inches apart.
The bucket’s width indicates the overall width of the paddle wheel was 5 feet 2
inches. The wheel fit into an 8 foot 6 inch wide opening in the guard with 20
inches of fig 34 fig 35 clearance on each side. The spacing of the paddle arms,
52 inches apart, is also the original spacing of the paddle flanges on the
paddle shaft. This measurement implies the flanges shifted as a result of
demolition work. The combined measurements of flange diameter and length of the
paddle arms suggests the paddle wheel diameter was approximately 29 feet.
A wooden piling rests over the entire length of the port shaft extending north
35 feet from the crank. It is probably a piling that once marked the site as a
navigation hazard but was later pulled out of the bottom and dropped on the
site. It has been left out of the site map (Figure 13) to provide an
unobstructed view of the shaft.
Architectural Window Glass
When built in 1851, the Maple Leaf incorporated many features common to
steamboats on Lake Ontario and the Great Lakes. Besides gross components, such
as the hull and steam machinery, many delicate decorative elements added to the
ship's personality, including decorative window glass. A contemporary source
praised the glass artist and designs he used on the Maple Leaf. “We are
particularly pleased with the profusion of stained glass, tastefully and
elaborately painted by our friend Mr. E. C. Bull, whose skill has covered every
glass door and window with pretty little sketches enwreathed with maple leaves,
which would form quite a study for the youthful artist” (DBW 26 March 1851).
This analysis includes both decorated and undecorated window glass fragments
recovered from the steamboat's aft deck in 1994. Initially, window glass was
differentiated from other types of artifact glass, such as bottles, glassware,
and lighting devises, which represented the ship’s cargo. Disqualifying features
included glass with mold marks, curvature, or embossing. Characteristics
ascribed to window glass include flatness, relatively uniform thickness, glazing
marks, specific seed bubbles patterns, and decorative treatments. This analysis
looked for specific evidence of window glass manufacture, decoration, and use as
an architectural component. Before discussing the findings of this subject a
summary of glass production, decoration, and installation is presented.
Production
Glass is defined as a supercooled liquid: "in vitreous bodies there is a gradual
stiffening of the liquid until the viscosity or stickiness becomes so great that
the behavior is that of a solid" (Armitage 1959:75).
Silica is the primary component in glass and generally derived from sand, quartz
pebbles, or flint. Prior to the twentieth century, the melting point of silica,
1,750°C, was too high for most furnaces to reach and maintain. A lower melting
point was achieved by adding an alkali flux in the form of plant ashes. Sodium
and potash were the most common fluxes (Newton et al. 1989:54-56). For example,
adding twenty-five percent sodium to silica lowers the melting temperature to
795°C (Armitage 1959:75). This soda glass is unstable and soluble in water but
by adding lime a more durable product, called soda-lime glass, is produced
(Newton et al. 1989:60).
Ideally, the ingredients used in glass making yield a colorless product.
Nevertheless, impurities in the silica or flux often give glass an unwanted
color. Iron, the most common impurity, imparts a greenish tint. Adding a
decolorant such as manganese or antimony lessens or eliminates the color (Newton
et al. 1989:59).
Glass production begins by placing the ingredients in a pot or crucible made of
refractory material and melting the batch in a furnace or kiln. The molten
material is called metal. From the early Roman period to the nineteenth century
window glass was produced by two different glass blowing methods. Crown glass is
made by spinning a gather of metal on the end of a pontil to make a disk of
desired thickness and size (Figure 36). The crown's center is marked by a boss,
or bull's eye, where the pontil attached to the crown. Fragments of crown glass
can be identified by circular ripples in the surface or curving lines of small
bubbles, called seed (Newton et al. 1989:55, 91-93).
The second type, cylinder glass, persisted as a manufacturing technique into the
twentieth century (Figure 36). The glass blower produces the cylinder by blowing
the gather into a globe. The gather is then suspended vertically while the
worker alternately blows, swings, and spins the growing cylinder. The weight of
the swinging molten glass pulls itself into a cylinder while the centrifugal
force of spinning gives it an even shape and thickness. When finished, both ends
are cut off and the cylinder is split longitudinally with a hot iron. The glass
is then reheated in a kiln and flattened into a sheet (Ericson 1926:112; Newton
et al. 1989:91). Cylinder glass can be identified by the elongated shape of the
seed bubbles which form straight parallel lines consistent with the longitudinal
shape of the cylinder (Newton et al. 1989:91-92).
Once a glass product is completed, whether window glass or any other glass fig
36 artifact, it must be annealed to relieve stresses which build up during rapid
and differential cooling experienced while working the metal. Glass that is not
annealed is weak, brittle, and prone to shatter during use. Annealing involves
reheating the object in a furnace and slowly cooling it off over a period of
several hours (Newton et al. 1989:63-64).
Decoration
While most of the window glass found on the Maple Leaf is undecorated, some has
been embellished with different types of decorative treatments. These include
coloring the metal during the manufacturing process, or painting and etching the
finished panes. Two techniques are used to color glass during manufacture and
both employ metals and metallic oxides as coloring agents. Pot colored glass is
made by adding metal or metallic oxide to the molten batch in the furnace. This
produces a uniform color throughout the glass. The second technique, called
flash, is effected by dipping a gather of uncolored glass into a batch of
colored glass. The gather is then blown into a cylinder or crown leaving a thin
covering, or flash, of colored glass on one side (Newton et al. 1989:95-96).
In both techniques, colors are dependent on many variables in the glass making
process; impurities in the batch, a reducing or oxidizing atmosphere in the
furnace, furnace temperature, concentration of coloring agent, and mixing
different coloring agents. Gold and copper produce ruby glass. Copper, as well
as manganese and cobalt, can make blue. Copper oxide combined with lead oxide
produces greens and manganese makes purple (Newton et al. 1989:57-59).
Standard panes of uncolored window glass can be embellished a number of ways,
including painting, staining, enameling, and etching, depending on the desired
effect. Paint is generally used to make dark opaque lines for drawing outlines
much like an ink drawing on paper. Paint consists of ground glass, iron oxide,
flux, and a binding medium, such as gum arabic, to make the paint flow and
adhere to the glass. Flux is necessary to lower the melting point of the paint
below the window glass. When the drawing is completed the glass is fired to fuse
the paint to the surface (Newton et al. 1989:96; Reyntiens 1967:57).
Staining and enameling also involve firing to produce colors on the glass
surface. In staining, silver nitrate is applied to a glass pane to produce a
range of yellow colors when it is fired. This technique was developed in the
fourteenth century to provide a way to incorporate more than one color on a
single piece of glass (Newton et al. 1989:99-100). Translucent enamels were
developed during the sixteenth century and became popular for the wide range of
colors available. Enamels are made by mixing finely ground glass powder with a
metallic oxide colorant. The ingredients are combined in a liquid medium and
painted on the window pane. When fired, the enamel fuses to the surface and
becomes a thin coat of glass on the window pane (Newton et al. 1989:97;
Reyntiens 1967:87).
Most of the enameled glass from the Maple Leaf is also acid etched to create
subtle surface decorations. These decorations appear as a dull mat finish on the
glossy glass surface. Etching is done with hydrofluoric acid which dissolves
silica. The window pane is prepared for treatment by applying a protective coat
of bee's wax to the surface. Next, a decorative design is scratched through the
protective wax to expose the glass below. The glass is then placed in a bath of
hydrofluoric acid to etch the exposed surfaces (Newton et al. 1989:73).
Glazing
When the finished crown or cylinder glass comes out of the annealing furnace, it
is cut to size before shipment to market. These glass panes are called lights (Ericson
1926:11). In 1817 lights were advertised in sizes 8 by 10 inches, 10 by 12
inches, and larger. Advertisements for 1847 mention lights measuring 21 by 25
inches and 24 by 30 inches. Generally size became larger throughout the
nineteenth century as cylinder glass replaced crown glass (Roenke 1978:35).
Cutting and installing window glass is done by a glazer. The glazer prepares for
glass installation by first measuring the opening for the light in the window
frame. The wooden frame is rabbeted to create a recess to hold the glass (Ericson
1926:53). Glass is cut by scoring the surface using a steel wheel cutter or
diamond tool. Once scored, the glass is broken by bending or tapping along the
cut. Using a dull cutting tool or pressing too hard with a cutter leaves a trail
of tiny splinters along the score and is considered a bad cut (Ericson
1926:26-27,46-47; Reyntiens 1967:48-51). Once properly sized, the pane is fitted
in the frame and secured in place with glazing putty. Putty is made from linseed
oil and whiting with white lead or zinc added for durability. A bead of putty is
placed around the edge of the window pane and smoothed with a putty knife to
fill the rabbet (Ericson 1926:57-60).
Findings
The glass discussed in this paper was found in a thick layer of shell hash
covering the aft main deck. The layer contained a high artifact concentration
including decorated and undecorated window glass. In the analysis, weight was
used instead of individual artifact counts. Given the fragmentary nature of the
glass, a minimum count of panes was not attempted. Hopefully, by using weight a
more accurate and quantifiable analysis can be completed. Table 1 lists the
glass types by provenience. In the following discussion, undecorated glass will
be examined first.
Undecorated Glass
Undecorated window glass makes up 79.8% (2462.0 grams) of the total glass
examined and is more prevalent than any other type. It all appears to be the
same type with a greenish tint caused by iron impurities. Thickness ranges from
0.064 to 0.12 inches with an average of 0.64 inches. Another characteristic is
the small seed bubbles which indicate the method of manufacture. The seed
bubbles are elongate and run in parallel lines showing the panes were made from
cylinder glass.
One unbroken pane from Recovery 109 can be used to extrapolate the approximate
size of other panes used on the vessel. The unbroken piece, part of artifact
number 05077, weighs 106.2 grams, measures 4.04 inches wide by 9.61 inches long,
and averages 0.07 inches thick. Two other broken pieces provide additional width
measurements. A fragment in artifact number 05151 is 4.10 inches wide, nearly
the same as the first. A narrower fragment is part of artifact number 05077 and
measures 3.28 inches.
| Recovery # and Artifact # | Plain Window Glass | Acid Etched/ Enamel | Acid Etched | Pot Color | Flash Color |
| R104/05011 05010 | 207.2g | 5.7g | 13.3g purple | ||
| R105/05049 | 172.3g | 1.3g | 11.9g | ||
| R108/05075 | 27.2g | ||||
| R109/05077 05079 | 811.7g | 56.8g green | 2.5g green | ||
| R110/05107 | 47.1g | 1.0g | |||
| R112/05134 05135 | 51.0g | 3.1g 1.0g |
|||
| R113/05151 05149 | 706.9g | 2.7g | 5.4g blue | ||
| R114/05163 05162 | 228.2g | 431.0g | |||
| R120/05211 | 202.6g | ||||
| R122/05227 05229 | 35.0g | 29.9g red | |||
| Total 3087.2g | 2462.0g | 432.3g | 52.6g | 75.5g | 32.5g |
| Percentage 99.1% | 79.8% | 14.0% | 1.7% | 2.5% | 1.1% |
Table 1. Distribution of window glass by type and provenience is given in
weight. Overall percentage by weight of each type is presented at the bottom.
Colored Glass
Small amounts of pot and flash colored glass are represented in the sample
(Table 1). There are three shades of pot colored glass; green, blue, and purple.
In addition, a very small amount of flash green was found. Green is the only
color found in both pot and flashed glass. Red, the fourth color represented, is
only used as a flash.
Seed bubbles on the pot colored green glass suggest it is cylinder glass.
Evidence of the manufacturing process used to make the flashed glass is
inconclusive. Most of the fragments are too small to hold an adequate number of
seed bubbles. Larger pieces contain seed bubbles elongated in random directions.
This may be a function of the flash process.
Acid Etched
A small amount of colorless glass has been acid etched and two patterns have
been defined. The snow flake pattern (Figure 37) is represented by one example
from recovery 108, artifact 05075. It is a repeating octagonal pattern. The size
of the original window could not be determined from the fragment. Seed bubbles
proved inconclusive for determining the manufacturing process.
The pinwheel pattern is part of recovery 112, artifact number 05134. Upon
recovery the glass was noted as being painted black on the rough etched surface
(Figure 37). Subsequent conservation treatment washed the pigment off. This
indicates the pigment was not fused to the glass by firing and was not very
durable. This is the only example of this decorative technique found on the
site.
Enameled/Etched Glass
The majority of decorative glass work found on the Maple Leaf falls under this
category (Table 1). This technique uses acid etching to create a design or
pattern on the Fig 37 glass. Colored enamel is applied to the opposite side to
highlight the patten and enhance the piece.
Besides the painted glass previously mentioned, all secondary, or post
manufacture, colored glass is enameled. Colors are primarily earth tones
dominated by browns, yellows, and pale greens. Two patterns are represented well
enough to recreate. The ivy pattern consists of vines and leaves (Figure 37).
Intact edges on one window pane fragment give a width measurement of 3.21
inches, nearly the same width as the uncolored fragment from artifact number
05077. Scratch marks on the enameled side run parallel to the finished edges and
were probably caused when the glass was cleaned with an abrasive cloth or
newspaper. More importantly, the scratches indicate the width of the glazing
putty used to hold the glass in the window frame. The narrow strip overlain by
the putty measured 0.22 to 0.25 inches wide. Seed bubbles indicate the pane was
made from cylinder glass.
Figure 37 illustrates the floral border pattern. This pattern was used to create
a border around a fairly large glass pane, leaving the center open for
additional decoration. Although the central decoration is very fragmentary, it
might represent a maple leaf. The example illustrated shows a corner fragment.
Cleaning marks are not present but a score mark from a bad cutting attempt is
present along one edge of the enameled side.
Several other patterns are present but are too fragmentary to reconstruct. The
etched surfaces appear to have floral motifs and different patterns can be
discerned by the motif style and enamel design.