4 o8 THE POPULAR SCIENCE MONTHLY. 



British Association for the Advancement of Science. Through 

 the urgency of Sir David Brewster and others it was set up in 

 the great exhibition of that year in London, where a medal was 

 awarded for it. It was adopted at the Greenwich Observatory 

 soon after, and speedily throughout Europe. The use of the "cir- 

 cuit interrupter " and the " chronograph " together constitute what 

 became known in Europe as " the American method " of record- 

 ing observations. Through it the errors for which the " personal 

 equation " is a partial remedy are largely eliminated, and a supe- 

 rior definiteness of record is attained. 



Soon after the electrical experiments of 1848, the " circuit in- 

 terrupter " was put to use at Cambridge in transmitting to Boston 

 and other points in New England the true local time. This was 

 the beginning of the Harvard Observatory time-service, which 

 was systematically organized in 1872. This idea was also early 

 adopted at Greenwich. 



In 1852 the officers of the Harvard Observatory co-operated 

 with Captain Charles Wilkes in experiments for ascertaining the 

 velocity of the sound from the discharge of cannon under differ- 

 ent atmospheric conditions. The object of this investigation was 

 to secure accurate values for some of the data obtained by the ex- 

 ploring expedition, the measurement of distances in some cases 

 having been made by firing cannon. 



One of the important events in the latter part of Prof. Bond's 

 directorship of the Observatory was the beginning of the publi- 

 cation of The Annals of Harvard College Observatory. This was 

 made possible by an endowment of ten thousand dollars given in 

 1855 by Josiah Quincy, ex-president of the college. The first of 

 these noble quarto volumes was issued in the following year, and 

 embodied a review of the work of the preceding years, so that the 

 whole series makes a continuous record from the establishment of 

 the observatory. 



Prof. Bond died January 29, 1859, and was succeeded in the 

 management of the Observatory by his son, George Phillips Bond, 

 who had been one of his assistants for many years. The elder 

 Bond had entered vigorously into the scientific life of his time, 

 and his labors were duly appreciated by his associates and con- 

 temporaries. He was a member of the American Academy of 

 Arts and Sciences, the American Philosophical Society, and the 

 Royal Astronomical Society of England. From Harvard College 

 he received the honorary degree of A. M. in 1842. 



