49 



with the daily rating of certain standard clocks by comparison 

 with the observations of the times of suitable stars, and 

 the work of the Time Service involves the daily issue of 

 time-signals to the General Post Office for distribution 

 throughout the country, and the dropping of time-balls at 

 Deal, and indirectly at Portsmouth, Portland and Devonport, 

 for signalling to ships at sea. 



The activities of Greenwich Observatory have extended 

 far beyond the grounds of the Observatory itself. The 

 expeditions in which the assistant, Charles Green, took part 

 have already been noticed, and later expeditions have been 

 quite on the same lines. Thus in the igth and 20th centuries, 

 not a few expeditions have been sent out from Greenwich, 

 or have come to Greenwich, in connection with the determi- 

 nation of the longitudes of various observatories overseas, 

 while the special opportunities presented by total eclipses 

 of the sun for extending our knowledge of solar physics 

 have been taken full advantage of in recent years. The 1914 

 Report refers to the preparations for the latest of these 

 expeditions, namely that to observe the eclipse of August 21, 

 1914, which was successfully observed, though under war 

 conditions, in Minsk, in Russia. 



" It will be seen then that fundamentally, Greenwich 

 Observatory was founded and has been maintained for dis- 

 tinctive practical purposes, chiefly for the improvement of 

 the eminently practical science of navigation. Other 

 inquiries relating to navigation, as, for instance, terrestrial 

 magnetism and meteorology, have been added since. The 

 pursuit of these objects has of necessity meant that the 

 Observatory is equipped with powerful and accurate instru- 

 ments, and the possession of these again has led to their 

 use in fields which lay outside the domain of the purely 

 utilitarian, fields from which the only harvest which could 

 be reaped was that of the increase of our knowledge."* 



It is hoped that the preceding pages, though they give but 

 a hint of its present activities, will have proved that Green- 

 which Observatory is a living institution. But the first 

 law of life is growth, and if the administrators of the Observa- 

 tory had been content at any time to restrict its development 

 rigidly to the purely utilitarian purposes for which it was 

 founded, it would have failed to have accomplished these, 

 and would have imperilled its own existence. But it has been 



* " The Royal Observatory, Greenwich, its History and Work," 

 p. 316- 



D 



