REPORT OF COMMITTEE OX OBSERVATORIES 1 47 



I think that it is of first importance to have a permanent obser- 

 vatory- furnished with a large refledbig telescope and a complete 

 equipment of auxiliar}- instruments for astrophysical research on 

 some site with the most favorable conditions of atmosphere. If this 

 were near the equator, it would command the richest regions of both 

 hemispheres. I mention this point in case it might not be found 

 possible to build a separate southern obser\'■ator5^ 



The observator}- next in importance, it seems to me, would be one 

 on the top of Mount Whitney, devoted especiall}" to solar work, or 

 chiefl}' so. I think the photographic method of getting the corona 

 should be tried. Theoreticall}' it is certain of success, if only the 

 atmospheric conditions are but a little better than normal surface 

 ones. 



I suppose work could only be carried on during the summer, but 

 if the conditions are as good as the altitude would suggest, there is 

 certainly work enough for many years to come. 



The observatory at the base might be regarded as temporary, and 

 perhaps might be given up when a sufficient number of obser\-ations 

 simultaneous with similar obser\'ations at the obser\-atory on the top 

 had been made. 



\_From Professof Arthur Schuster, Director of the Physical Laboratory^ 

 Owe7is College, Manchester, England^ 



February i8, 1903, 

 In answer to your letter of the 28th January : I should, of course, 

 be highl}' pleased if funds were to become available for the important 

 work sketched out hy you. Taking the different points of yowx let- 

 ter in order : 



I. I have recentl}- looked carefully over a good deal of literature 

 concerning solar radiation, and I confess I have not been impressed 

 by the probability that simultaneous obser\-ations at high and low 

 altitudes will help us very much. The differences which such 

 observations could show would all be due to the layer of air included 

 between the two levels. On different days the atmospheric condi- 

 tions of that layer may be very different, and 3-et the atmospheric 

 conditions at greater heights than, say 15,000 or 20,000 feet, might 

 be the same. You would at once have errors introduced, and the 

 obser\^ations at the high altitudes might hy themselves give you 

 better results than the combination. You must face the fact that it 

 is impossible altogether to eliminate changes in atmospheric condi- 



