THE TIME SERVICE OF VARIOUS COUNTRIES.

. The knowledge of the exact time is of the utmost importance for the transaction of the business affairs of all the nations; especially so for those who have charge of the means of transportation and of rapid communication. This is the case for railroad and telegraph companies and especially for maritime commerce. The captains of vessels, at the moment of clearing for sea, must be able to regulate their chronometers with precision, for upon these instruments depends the determinations, during their voyage, of the geographical positions of their vessels. Accordingly, at the principal ports of the world, a special device (time ball) is used to give the mariners the exact time at known moments. Indeed, in certain ports, special bureaus for this purpose are at the service of sea captains during their stay in port; here they may deposit their chronometers so that their conditions and daily rates may be determined. These time-service bureaus are generally in direct communication with an astronomical observatory, which assures them of the time used.

Various countries of the world have organized, according to their means and local necessities, more or less extensive time services.

Generally, in countries covered by a network of telegraph and telephone lines, a service is established such that the various bureaus connected by wire receive daily the necessary time signal. Those wishing signals can apply to these offices or rely on time furnished to exterior clock dials either at railroad stations or at post offices.

In the United States of America the time is sent over all its immense extent of land. It is transmitted at noon by an accurately regulated pendulum which automatically sends currents of electricity over all the telegraph lines of the country. These currents actuate receiving instruments at all the telegraph stations. The duration of the transmission lasts five minutes. They are sent out from the Naval Observatory at Washington for all the region east of the Rocky Mountains, and from the observatory at Mare Island, Cal., for that to the west. Besides these noon signals, others can be sent during the course of the day when required.

In Portugal the Lisbon-Tapada Observatory furnishes telegraphically the time to the whole country, to the time ball at the arsenal at Lisbon, and to the chronometer station of the meteorological observatory of Ponta Delgada (S. Miguel, Azores).

In Belgium the time is sent daily by telephone to the time-service office at the port of Antwerp where an assistant is detailed to compare such chronometers as may be deposited. An accurate Riefler clock serves to maintain the requisite time and work the time ball. The observatory sends the time also to the central bureau of the tele

graphs which in turn distributes it to all the telegraph and railroad stations of the kingdom.

The precise time is sent also to the various civic departments as well as to certain private institutions to which it is essential. The transmission of the time is made as follows: As soon as the one in charge of the station is in telephonic communication with some one wishing the time, he states the time he is going to indicate, to the exact minute generally, then, 10 seconds before that time he calls, "attention," and then accurately at the minute he says, "tip." His "tip" is rarely out by two-tenths of a second.

SOME RECENT INTERESTING DEVELOPMENTS IN

ASTRONOMY.'

By J. S. PLASKETT, B. A.,

Dominion Observatory, Ottawa, Canada.

It has been the custom for the newly elected president of an astronomical society to give in his inaugural address a review of the progress of the science of astronomy during the year just closed, and I am partly complying with that custom in what I have to say to you to-night. I do not propose, however, to attempt to give you a review of the whole field of astronomy. That would be quite impossible in one address. All I shall attempt, therefore, is to select from the material at hand some of the most important results recently attained, and from these again those which are likely to prove of the greatest general interest. In this selection, it is very likely that I shall be guided by my own particular preferences, and I do not, therefore, claim that what I have to lay before you will be entirely representative of the progress of the science.

In my opinion there has been no time in the history of astronomical science when progress has been so rapid and when we seem to be on the eve of so many interesting developments, and I might almost say generalizations, as at the present time.

One of the most significant indications of such development in astronomy is the remarkable coordination and correlation that is being so rapidly developed among the different sciences. A few years ago the astronomer made no use of any science but his own, with, of course, its indispensable adjunct mathematics; but now progress in astronomy is impossible without the aid of physics and chemistry, geophysics and geology. We do not know, indeed, how soon we shall be applying biology, with its allied sciences, in the study of such a subject as "Life in other worlds," on which we had recently such an eloquent and instructive address by Prof. Aitken. Another significant fact pointing toward rapid developments and deductions is the completion or approaching completion of many

1 Address before the Royal Astronomical Society of Canada, Ottawa. Feb. 23, 1911. Reprinted by per. mission from the Journal of the Royal Astronomical Society of Canada, July-August, 1911, pp. 245–265.