RESUL TS OF BRITISH TRANSIT EXPEDITIONS. 79 



stand by each other, a chief in one department commend- 

 ing the zeal and energy of the chief in another department, 

 this chief in turn commending the industry and ability of 

 the other, and so forth, while subordinates of all ranks 

 might be apt either to maintain a judicious silence, or else 

 at least to avoid any utterance which would endanger their 

 position. It may, on the one hand, be to some degree 

 questioned whether it would be fitting that discipline should 

 be so far neglected in such a case that a subordinate should 

 have eyes to see, or ears to hear, or thoughts to note, any 

 error on the part of his superior in office. And on the other 

 hand, those who know little or nothing of astronomy can of 

 course form no opinion on astronomical matters, however 

 high they may be in authority outside matters scientific. To 

 assert, then, that it is either improper or undesirable for unoffi- 

 cial astronomers to comment on the plans or results of 

 astronomers employed and paid by the nation is practically 

 equivalent to asserting that it is improper or undesirable for 

 the work of these paid astronomers to be examined at all, 

 a conclusion manifestly absurd. 1 



1 The following lines are from a letter of mine, which appeared in 

 the Times of April 13, some time after the present article was 

 written : 



' A few months ago I said in these columns that the determination 

 of the sun's distance, then recently communicated to Parliament 

 namely, 93,375,ooo miles was probably some 800,000 miles too 

 great ; and I spoke of the method on which the determination was 

 based as to some degree discredited by the wide range of difference 

 both between that result and the mean of the best former measure- 

 ments, and between the several results of which that one was itself the 

 mean. Captain Tupman, as straightforward as he is skilful and 

 zealous, announces as the result of a re-examination of the British 

 observations a distance about 600,000 miles less than the above, or, 

 more exactly, about 92,790,000 miles, as the sun's mean distance. But 

 while he obtains from the ingress observations a mean distance of only 

 92,300,000 miles, he obtains from the egress observations a mean 

 distance of about 93,040,000 miles ; and the value, 92, 790,000 miles, is 

 only obtained as the mean of these two values duly weighted, the egress 

 observations being more satisfactory than the ingress observations. 



