JF Ptak Science Books Quick Post
Looking for illustrations of an enormous horse-drawn rangefinder in volume 7 (1879) issue of the Scientific American Supplement I came across these two unusual images of a hand-powered sleigh and "bicycle". The gearwork looks to be about the size of a modern bike wheel, perhaps even bigger--it certainly weighs more, and could weigh more than an entire (good) bike. I don't really understand how the energy is transferred but it seems to be that the gear drives a toothed rod back and forth that reacts with a springed mechanism that in turn moves the wheels. It is a huge gearwork, but that vehicle looks awfully big and not-so-mobile to be driven by that and the springs. On the sleigh the gearwork seems to push a plane of some sort to push the sleigh forward. Even in 1879 there were better and simpler designs for bikes...I don't know what to say about the sleigh....
From the SA:
"The improved propeller we illustrate to day is the invention of Mr TA Zoebl of Milwaukee and is equally applicable to sleighs and ordinary velocipedes. As will be seen from our engraving the velocipede of Mr Zoebl consists of two large wheels and a smaller wheel. The latter may be turned to the right or left means of two steering rods acting on a movable cross piece as the illustration shows the rider pressing with the foot on one or the other side at the end of the rods. When acted upon thus the wheel is held in a position parallel with the large wheel by springs surrounding the steering rods. Thus the wheels cannot get out of their track very easily. The propulsion is effected by a system of toothed wheels operated by hand by means of cranks and acting upon propelling rods taking effect directly on the ground are forced back to the rear part of the vehicle by powerful springs and alternately lifted up and pulled forward by the revolutions of the driving mechanism. By pressing on knob provided alongside of the seat the propelling rods are firmly pressed to the ground thus acting as brake by which the velocipede can soon be brought to a stop. When the pressure on the knob is released springs provided for that purpose raise the propelling rods from the ground again. To adapt this device to a sleigh the steering apparatus must be changed correspondingly as indicated in the drawing."
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