THE GRAPHIC METHOD 81 



gear and through a pinion drives the friction-plate 

 gear. Slow speeds are then obtained. 



These operations are easily and rapidly performed, 

 though, as in all gear mechanism, an instant's pause 

 is sometimes required to enable the gear teeth to 

 engage. The clockwork should be in motion, without 

 the fan, when the adjustments are being made. 



With both fast and slow gearing four fans of 

 different areas may be used. They are slipped upon 

 an extension of the last pinion shaft in the chain. 

 Five slow and five fast speeds (exclusive of spinning) 

 are thus obtained. An additional slow speed (50 cm. 

 per hour) may be obtained with a very large fan. 

 All speeds are regulated by a friction governor fast- 

 ened to the same shaft that carries the fan. With 

 one winding the drum will revolve from about one 

 to about seven hours, or longer, depending on the 

 fan employed. 



The Long Paper Kymograph. 1 In Fig. 19 the 

 kymograph is arranged for use with a sheet of smoked 

 paper about eight feet long. A rigid bench of steel 

 about 97 centimetres long firmly supports two 

 ^-shaped castings in which two aluminium drums 

 revolve on pointed adjustable bearings. One of the 

 castings slides along the bench, and may be fastened 

 at any desired distance from the remaining or clock- 

 work drum, so that paper from about 150 to 240 

 centimetres in length may be stretched between the 



Science, 1906 



