io 8) 
Wrans. Ne 3. AC Scr: 6 Jan. 16, 
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-signals 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, by 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 
success on account of its cheapness. It is to be said, however, that 
the time required for the impulse to travel from the reservoir to 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 obsrrvatories 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- 
distributing centres are as follows: 
1. The Naval Observatory System of Washington, D. C. This 
system drops a noon-time ballin 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 Company, 
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 building, 
and furnishes all the railroads entering Boston, and other roads, with 
clock signals.4 
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.® 
