360 HISTORY OF ASTRONOMY. 



the writing of all, without change of adjustment. A 

 clock in Washington, prepared by Mr. Saxton, graduated 

 the time scales on the Morse registering fillets at all the 

 stations, and arbitrary signals were given at one station, 

 and received at all the others. Thus Pittsburg, Cin- 

 cinnati, Louisville and St. Louis, were successively, for a 

 period of ten minutes, made the stations for arbitrary 

 signals, which were printed on all the registers every 

 three seconds. These observations have been carefully 

 analyzed by Mr. S. C. Walker, by Dr. B. A. Gould, and 

 by Mr. K. Kullman, of the Bavarian engineers. Mr. 

 Walker's final conclusion is, that the velocity of the 

 galvanic wave in the iron wires of the telegraph lines is 

 15,400 miles per second; and that the velocity of the 

 wave in the. ground is not more than two thirds of the 

 velocity in the iron wires.* Dr. Gould obtained as 

 the most probable result, a velocity of 14,900 miles per 

 second through iron wire, and he concluded that the 

 signals were in no case transmitted through the 

 ground. f Mr. Kullman obtained a mean result of 

 13,000 miles per second in iron wire, and 9,740 in the 

 ground.^ 



From the experiments of February 5, 1850, between 

 Washington and Charleston, Dr. Gould deduced the 

 velocity of the electric current equal to 16,856 miles 

 per second. 



* Coast Survey Report for 1850, p. 87. 



f Proceedings Am. Asso. at New Haven, p. 92. 



\ Ibid., p. 401. Ibid., p. 97. 



