SCIENTIFIC QUARRELS 171 



satisfaction to me that Dr. Herschel last year found 

 my discovery of the morning and evening twilight of 

 Venus's atmosphere to be confirmed, as I could not 

 hope to have obtained such an important confirmation 

 so early, considering the excellent telescopes required, 

 and that a favourable opportunity for such observations 

 occurs but seldom : yet the paper on the planet Venus, 

 which this great observer has inserted in the Phil. 

 Trans, for 1793, contains unreserved assertions, which 

 may be easily injurious to the truth, for the very 

 reason that they have truth for their object, and yet 

 rest on no sufficient foundation." And Schroeter then 

 endeavours to show that Herschel's paper contains 

 misrepresentations or unsatisfactory proof of mistakes 

 committed by him. 



It was a small quarrel at the worst, in which these 

 two friends engaged, a very different quarrel from the 

 disputes and angry encounters that disgraced Leibnitz, 

 and Bernoulli, and Flamsteed, and did not leave 

 Newton altogether unscathed. Schroeter had perhaps 

 the best of it. His mountains, twenty or twenty-three 

 miles high on the surface of Venus, may be a myth, 

 but there is no doubt that his measure of the length of 

 her day, 23 h 21 m , is somewhat grudgingly accepted by 

 Herschel, while his estimate of the size of Venus, as 

 rather less than the earth, is preferred to Herschel's, 

 who believed he had proved Venus to be a little larger 

 than the earth. At the same time it must be admitted 

 that Herschel had sometimes cause to complain. 

 Writing of one astronomer in 1799, he says, "the same 

 author's account of my double stars is extremely 

 erroneous." 



As early as 1777, while toiling at the daily work of 



