54 F. K Nipher — Arrawj<>nnntf<>r tr<< remitting clockrbeaU. 



[Read before the St. Louis Academy of Science. March 20th, 1882.] 



A SIMPLE device for the tram-mission of clock-beats upon 

 telegraph lines lias been found >.»-•-■,, torv in n- action, i \ 

 a description is here given for the benefit of any to whom it 

 may be of service. The break-piece, which is represented in 

 the cut. is best attached to the lower end, p, of the pendulum. 

 It consists of a small brass bar which is screwed to the end of 

 the pendulum rod, and set with a "jam nut" below. Two tr- 

 ips of brass (u) arc slipped around the vertical sides 

 of the bar.' to which they are clamped bv bolts. The U strips 

 arc sh t ted to ; dmit ol Ian nil admstm :nt, as shown. Stiff strips 





of brass (s) are soldered to the bottoms of the U pieces, and 

 carry the two blades B which terminate helow in platinum 

 sheets p. It is evident that the adjustment of the slotted U 

 pieces enables one to adjust the width of the gaD between the 

 blades B. For telegraphic transmission, where the - . 

 repeated, with a pendulum vibrating so that the amplitude 

 chord is 2 inches, the interval between the blades should be 

 about T T „ inch, while for chronographie work it should be some- 

 what smaller. 



The mercury is, as is usual, contained in the hollow screw c, 

 which is carried by the bed plate b. The screw c is tipped 

 with a cylinder of wood or vulcanized fiber, and the mercury 

 cavity terminates at the top in a long, narrow slot, at right 

 angles to the plane of vibration. 



This break is now in daily use by Professor Pritehett at the 

 Observatorv < I Washington University, and the clock-beats are 

 sent over something like ten thousandmiles of wire. Arrange- 



