TIME 



5 



movements have to be observed at a distance and 

 transmitted to the corresponding recording needle. 

 For this purpose transmission by air is employed and 

 found preferable to transmission by electricity. The 

 following apparatus effects this object. 



Two similar apparatuses are coupled together by 

 pneumatic connecting tubes, and the whole apparatus 

 goes by the name of " lever-drums." * Each part con- 



FiG. 2. — Arrangement deigned for transmitting a movement to the needle, which 

 records the duration and tae pluses. 



sists of a metal capsule, with a gutta-percba membrane 

 stretched over the top ; a lever is attached to the 

 membrane by means of a jointed crank. If the first 

 lever is pulled by the hand and lowered, the air in the 

 first tambour is compressed and passes into the second, 

 the corresponding lever is raised, and reproduces in all 

 its phases the traction exercised on the string. On 



* Usually called "Marpy'a Tambours," in .England. — Translator. 



