Fort Vancouver National Historic Site in Vancouver, Washington (near
Portland, Oregon) contains the remains of a 1829-1860 Hudson's Bay Company
trading post, headquarters, and supply depot.  The park is currently
researching the history and archaeology of the ca. 1832 powder magazine.
The historical record identifies a magazine variously as a vaulted brick,
brick and stone, or stone structure, about 18 ft. square.  Excavations in
1947 (Caywood) and 1972 (Hoffman and Ross) identified a foundation composed
of stone rubble and coral-derived lime placed in a shallow trench filled
with silty clay.  Hoffman and Ross (1974:81) suggest that the foundation
was made from a shallow trench, approximately 2 ft. wide, soaked with
water, then filled with stone rubble mixed with coral lime. A large, flat
stone laid and centered along the northern wall may represent a sill for a
door. Bricks did not appear to be part of the foundation, but were probably
associated with the walls of the structure above.  These were almost all
British statute-size bricks which are consistent with Gurke's (1982) Type
01 brick. Post casts were identified in the southeast (Feature 483) and
northeast (Feature 491) corners of the rubble fill foundations.  The casts
were 10 in. (25 cm) square and were excavated deep below the Magazine
foundations (1.4 to 1.5 ft. [43-46 cm]).  Contrary to Caywood's (1947)
findings, these features suggested squared timbers, and only a single cast
was recorded in the southeast corner (as compared with the two post casts
shown in Caywood's 1947: Plate 3).  There was very little wood found in the
casts.  Caywood's excavations previously identified posts in the northwest
and southwest corners of the foundations.

The function(s) of the posts on the outside edges of the stone foundation
is unknown.  Does anyone have other examples of excavated small brick
structures with post casts and have some good ideas on how these posts may
have functioned?  We are also interested in brick bonding patterns, brick
vaulting, flooring, roofing and other architectural details.  We have one
image that shows that the structure had a pyramidal roof and there is some
tenuous evidence for tin-shingled roofing (for fire-protection).  Other
people's experience with archaeological or still-standing structures from
the 18th or 19th centuries would be greatly appreciated.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Douglas C. Wilson, Ph.D.
Archaeologist
Vancouver National Historic Reserve
Fort Vancouver National Historic Site
612 East Reserve Street
Vancouver, Washington 98661

Phone: (360) 696-7659 x24
Fax:  (360) 696-7657