Great stuff! I still don't know how you find all these things, especially the images. I've been looking again and found the Dart and Paper Dart in "Cassell's Book of Indoor Amusements" (1881) and its source book "The Popular Recreator" (1873). Maybe the "inventor" of patent US613386 (granted not long after in 1898) found it in there, because it seems very closely related. Also it's interesting that the patent describes both the Preliminary Base and Waterbomb Base versions of the dart flight (the latter being preferred because it offers less air resistance).
Great stuff! I still don't know how you find all these things, especially the images. I've been looking again and found the Dart and Paper Dart in "Cassell's Book of Indoor Amusements" (1881) and its source book "The Popular Recreator" (1873). Maybe the "inventor" of patent US613386 (granted not long after in 1898) found it in there, because it seems very closely related. Also it's interesting that the patent describes both the Preliminary Base and Waterbomb Base versions of the dart flight (the latter being preferred because it offers less air resistance).