REPORT OF COMMITTEE ON OBSERVATORIES 45 



the object glass was most obligingly loaned by The Alvan Clark and 

 Sons Corporation of Cambridge, Mass. , and of which the principal 

 parts of the mounting were also loaned by the Lick Observatory, 

 thus reducing the expense of the telescope to a nominal sum. With 

 this telescope the character of the ' ' seeing ' ' is ascertained by sys- 

 tematic tests at all the stations visited. This can be compared with 

 the excellent conditions prevailing on Mount Hamilton, where Mr. 

 Hussey has had many years' experience. 



Pending Mr. Hussey 's examination and report, it scarcely seems 

 worth while to enter into a detailed discussion in regard to sites at 

 the present time. If the proposed Southern Observatory should be 

 organized upon a scale sufficient to secure the execution of the 

 greater part of the works enumerated in our program, the question 

 of site would be very important indeed, and we have so regarded it. 

 It is essential that the climate should be healthy for astronomers 

 engaged upon tasks so strenuous ; that there should be a large pro- 

 portion of clear nights ; that the air should be reasonably transparent 

 and exceptionally steady, and that, so far as possible, the ordinary 

 comforts of civilization should be found in the environment of the 

 observatory. In the search for a stimulating and healthful climate, 

 and also in the interest of the meridian observations, it would be 

 desirable to choose a latitude of 40 south or more. 



But in the southern hemisphere, in latitudes south of — 35 ° or 

 — 40 , the amount of cloudiness is apt to be very great, or the cli- 

 mate is otherwise unsuitable. In other respects, as in what was 

 formerly called Patagonia, some of the localities in high southern 

 latitudes cannot be regarded as available. The vicinity of Hobart 

 Town, Tasmania, offers many advantages, especially in the health- 

 fulness and uniformity of its climate, but with the disadvantage of 

 rain falling on nearly half the days of the year. The amount of 

 clear weather in New South Wales, though superior to that of our 

 Atlantic seaboard, is not quite all that could be wished. The ob- 

 ject of the proposed observatory is to secure valuable observations 

 in large masses by the expenditure of great energy during a com- 

 paratively short term of years. This qualification is not the only 

 one, however, and may possibly be regarded as compensated some- 

 what if a locality can be found where the climate is healthful and 

 where efficient routine assistants can be recruited from the sur- 

 rounding population. 



The funds appropriated for the use of the Commission will suffice 

 for what it has undertaken to accomplish ; but if site explorations 



