Paper, regarding four points to consider when constructing a bridge over a large navigable river by John Allen Allen presents four points to consider when constructing a bridge over a large navigable river, which include the current of the water, 'that the navigation of the river be not incommoded, or render'd dangerous in passing the bridge', the cost of building and maintaining the bridge, and the 'strength, stability and duration' of the bridge. Subject: Civil engineering Read to the Royal Society on 8 May 1729 1729