34 



Signals/or longitude by telegraph ielween Hamilton, Nev., and San Francisco, Col., November 19, 1869. 



It may be considered as a distinctive feature of the present reconnaissance that, althongli the 

 instruments for taking astronomical observations have been limited to sextants and chronometers, 

 yet, by the use of the telegraph, results have been attained that compare favorably with those that 

 would be expected from a more extended series of observations with more perfect astronomical 

 instruments, and opportunity afforded for determining with more certainty the rate of the chro- 

 nometers upon which the lesser or greater accuracy of the approximate longitudes to the south- 

 ward depend. 



