Trans. N. Y. Ac. Sci. 86 Jan. i6, 



THE INTERNATIONAL TIME-SYSTEM. 



For the past thirty years, observatories situated in different parts of 

 the world have undertaken to " give time " to their adjoining sections 

 of country, by the use of the electric telegraph.' 



At this present moment, prominent places in England and Scotland 

 receive their time-sigrals from the Royal Observatory at Greenwich, 

 There is but one standard time for the island, viz., the Greenwich time 

 — Ireland probably gets her time from the Observatory at Dublin. 



In Paris the Observatory clock controls by electricity many secondary 

 clocks of fine workmanship distributed throughout the city. 



There is also in Paris another system for distributing time, viz., the 

 Pneumatic system. Dia's in private houses, on the streets, etc., are 

 •connected by pipes with a central reservoir containing air. From this 

 reservoir, bv proper mechanism, is sent every minute an impulse, which, 

 compressing the air in the pipes, moves the minute-hand of each dial 

 forward one minute-space. The system has met with great popular 

 succrs> on account of its cheapness. It is to be said, however, that 

 the time required for the impulse to travel from the reseivoirto any 

 dial is appreciable, and varies with the distance of the dial from the 

 central reservoir. Some of the dials are therefore ten to twenty sec- 

 onds slower than dials near the impulse-generator." From many 

 other obs' rvatories in Europe radiate time-systems of greater or less 

 •extent. 



In our own country, the observatories at Washington, Cincinnati, 

 ■Cambridge, Albany and New York, began about twenty-five years ago 

 to furnish time to railroads, jewelers and government offices. The de- 

 mand for accurate time has increased each year, until now we find 

 many widely extended systems. The most important of these time- 

 distribu'ing centres are as follows : 



1. The Naval Observatory System of Washington, D. C. This 

 system drops a noon-time bill in Washington, furnishes time to the 

 government and city offices, and to the railroads. The Observatory' 

 clock can be connected with the wires of the Western Union Comoaiy, 

 so that time-signals can be sent to any part of the United States.^ 



2. The Harvard Observatory System, Cambridge, Mass. This 

 supplies time to many business houses in Boston, drops a noon-time 

 ball from the roof of the Equitable Life Insurance Company's buildmg, 

 and furnishes all the railroads entering Boston, and other roads, with 

 clock signals.^ 



3. From Allegheny, Pa., Professor Langley sends time to Pittsburg, 

 and also to the Pennsylvania Railroad.* 



4. The Dudley Observatory at Albany furnishes time to Albany, and 

 to the New York Central Railroad.*^ 



