ADDITIONAL STRUCTURAL FEATURES OF THE FORT WASHINGTON POWDER MAGAZINE by

Transcription

1 ADDITIONAL STRUCTURAL FEATURES OF THE FORT WASHINGTON POWDER MAGAZINE by RAYMOND S. BABY and RICHARD C. KNOPF In October, 1952, when an excavation was being made for the Western and Southern Life Insurance Company's parking garage at the northeast corner of Broadway and Third Street, timbers were pulled out from what appeared to be a pioneer structure. Investigation revealed the powder magazine of old Fort Washington, buried for nearly one hundred and fifty years. Originally the powder magazine consisted of two sections a superstructure above the surface of the ground, and a sub-surface portion beneath the original grade. Unfortunately, the superstructure was completely destroyed in the course of the recent excavation. Inquiries as to how the logs were placed originally led to no coherent or fruitful results. Therefore, this portion of the magazine must be forever a mystery. One can only note that the logs, which were laid in a horizontal fashion, were notched in a square manner at the ends. The sub-surface construction, however, is an entirely different matter. Enough timbers were salvaged and sufficient data were gathered adequately to reconstruct this portion of the magazine. At this juncture, it is unnecessary to give the details of the actual construction method of the sub-surface structure. That has been done already (See: "Fort Washington, Re-discovered," in January, 1953, issue of the Bulletin). Rather, what remains to be done is to describe the additional timbers and to show how they were used in relation to one another. The pentagonal-shaped magazine was built in such a way that corner posts were erected at each angle with one exception. This single exception was found in the case of the long side of the magazine, which ran generally northeast-southwest and parallel to the end of the barracks building. In this case, because of the length of the side and the necessity of the stronger support, a vertical post was dropped in the center of the side. This was quite evident, as the post was found and the outline of the planking un-

2 Fig. 1. Picture showing the ends of the corner posts. Note the dowel holes where they were fitted into the base of the structure. Note also the numbering method used. (Photo by Ohio State University Photography Lab., negative with the Anthony Wayne Parkway Board.)

3 Fig. 2. Close-up of a corner of the powder magazine showing the doweling of the horizontal cross-members, the jointing of the base of the magazine, and the siding. (Photo by Ohio State University Photography Lab., negative at the Anthony Wayne Parkway Board.)

4 Fig. 3. Picture showing Ray Baby, archaeologist of the Ohio State Archaeological and Historical Society with an angle of the Fort Washington powder magazine. This demonstrates how the horizontal cross-members, corner posts, siding, and base of the magazine fitted together. (Photo by the Ohio State University Photography Lab., negative at the Anthony Wayne Parkway Board.)

5 Fig. 4. Close-up of one of the base timbers, showing the angle, the doweling process used in the corners for both the corner posts and the base timber. Note also the trough cut in the base timber into which wasfittedthe siding of the powder magazine. This trough was, as will be noted, cut by an auger, the remaining portions carved out later to form the trough. (Photo by the Ohio State University Photography Lab., negative at the Anthony Wayne Parkway Board.)

6 Additional Data on Fort Washington Powder Magazine 325 covered during the investigation. The other sides were constructed as described in the above-mentioned article. However, additional data which have subsequently appeared attest to the engineering skills and careful planning of the powder magazine. The first of these is the numbering of the vertical posts. On all except one extracted appeared Roman numerals cut into the wood at the base of each post. (See: fig. 1.) These evidently corresponded to the numbers of the doweled ends of the base sills of the magazine. This numbering assured a perfect fit. The second interesting discovery was that of the base sill itself. Three complete pieces of the sill were recovered. (See: figs. 2, 3, & 4.) Each, as illustrated, had an angular cut end and a two-way dowel system. In other words, the angular ends interlocked to form a corner of the magazine, being doweled together for security. On top of the angle rested the corner post, which was likewise doweled in the corner angle formed by the two interlocking portions of the sills. On the top side of the sill was cut a trough 2 J inches deep and 2 inches wide. This was made by an auger, the intervening portions between the auger holes being chiselled out. When completed, the vertical planking was set firmly in this trough. Thus this report, together with that presented in the January, 1953, issue of the Bulletin, completes the available structural data concerning the sub-surface of the Fort Washington powder magazine.