On 10th Street, a little way east of 10th’s intersection with Hunter Road, near Towanda, we recently found a tiny stone arch culvert. This culvert has a span of only about four feet or so, and crosses a little, nondescript low spot, but is easily spotted due to the large concrete curbs that have been added atop. As far as stone bridges in Butler are concerned, it is far from imposing, though its miniature size gives it an appeal in its own right. Possibly one of the most interesting features of this culvert, however, is the fact that it obviously has been widened long ago with an adjoining stone arch section.
The 10th Street stone culvert was presumably built by Towanda Township, though we are unable at this time to find any newspaper references to it. The north face features surprisingly good masonry, all things considered, and the stones must have been at least roughly trimmed to achieve such a good fit at such sharp angles.
The south face of the structure is of a much cruder build.
This south face appears to have been added on later, judging from its width, which is much narrower than that of the north section; too narrow, it would seem, to ever have been intended as a complete culvert in its own right.
Probably the most interesting feature of the extension of the culvert is the fact that concrete was obviously poured in to make the angles between the stones. This is like the modified “Sharp arch” we experimented with and discussed in a previous post. While not, perhaps, as durable as true masonry, this method of arch building has the potential to last for years, even a century or more, as this culvert proves.
The Towanda Township 10th Street culvert has been added to our list of Butler County stone bridges, map number 33.