The Three Secretaries 213 



Observatory clock " ; and to this was added the supply of 

 the time to the adjacent cities by a system which made it 

 accessible to every inhabitant. 



The Pennsylvania was the first great railway to establish 

 and put into effect a systematic and permanent plan for the 

 simultaneous transmission of time signals throughout its 

 entire line, and to Mr. Langley is due the credit of first 

 successfully solving the problem of transmitting time 

 signals over this American line, many times greater in 

 extent and much more complex in character than the com- 

 paratively short English railways, where by the method 

 then in vogue the accuracy of the clocks in the inter- 

 mediate stations depended entirely upon a comparison 

 with watches, which, after being set by the standard clocks 

 in the terminal stations, were sent out along the line by 

 trainmen charged with the duty of regulating the time- 

 pieces and reporting inaccuracies. 



The present system by which the railroad service of the 

 whole continent is regulated may be said to be an out- 

 growth of that developed nearly thirty years ago at Alle- 

 gheny by Mr. Langley. In a letter to Mr. Langley dated 

 May 27, 1872, William Thaw, Vice-President and execu- 

 tive officer of the Pennsylvania Company, and Chairman 

 of the Board of Trustees of the Allegheny Observatory, 

 wrote : "I regard the time service as peculiarly your crea- 

 tion and dependent solely on you." Mr. Thaw also stated 

 that he had communicated the fact officially in writing in 

 a report to the Board. 



The income thus derived from the regulation of the time 

 service was applied exclusively to the uses of the Allegheny 

 Observatory, which obtained from this source almost all its 

 regular means for original research, amounting during the 

 administration of Mr. Langley to more than sixty thousand 



