30 president's addbess. 



brought about by condensation of meteor swarms due to gravity, 

 so that the existing distinction between stars, comets, and 

 nebulee, rests on no physical basis — all alike are meteoritic in 

 origin, the difference between them depending upon differences 

 of temperature, and in the closeness of the component meteorites 

 to each other. These suggestive opinions of so distinguished 

 an astronomer are deserving of every consideration, though 

 scientific imagination must necesarily have an important influence 

 in speculative questions of this nature. 



I have remarked, on a former occasion, that the romance of 

 astronomy is always a subject of attraction to early students of 

 the stars, and that the study of the science is most fascinating 

 when the object to be obtained is a real scientific acquaintance 

 with the countless luminaries visible overhead on a clear autumn 

 or winter night. But what I wish to do now is to pass over the 

 romantic portions of the science, and to devote a few words on 

 the connection of astronomy with our daily life. I shall thus 

 be able to show you that although there may be some imagina- 

 tion employed in the solution of imperfect or doubtful data, 

 astronomy is yet a necessary help to us all in our domestic and 

 business occupations. Anyone can realize the great advances 

 made in electrical science, for he is continually reminded of them 

 by the practical benefits derived from the use of the electric 

 telegraph and the telephone, but how few there are who connect 

 astronomy with anything that is practical. And yet it is 

 employed in various ways unknown to the general public. 

 The clock-time exhibited by every public clock, by your 

 household timepieces, and even by the watches in your pockets, 

 would soon go astray were it not that the astronomer at 

 Greenwich is ever referring his standard timepiece to the 

 unerring great star-clock. Daily he is on the watch for an 

 opportunity to make this necessary comparison, so that he may 

 be in a position to disseminate true Greenwich time throughout 

 the country. This is accomplished by means of an elaborate 

 system of galvanic time-signals, which are transmitted from the 

 Royal Observatory, at stated times, to all the principal post 

 offices and railway stations in the kingdom, through the wires 

 of the Post Office telegraph department. Time-balls, giving the 

 correct time, are dropped daily at various places by a direct 



