CORRESPONDENCE. * 229 



tlie professioual reputation of oue wliose whole income cle2)ends on the 

 remuneration received from the work of Lis hands, I was bound to 

 defend that reputation to the best of my ability, and I will. Either 

 Mr. Wenham or myself must " come off second best." 



Mr. Wenham now asks me to send him the objective again for 

 another trial. This is cool. I will make a substitute proposition. 

 Mr. Wenham may send his twenty-year-old objective here, together 

 with (if he pleases) any other that he has made since,* and they shall 

 be as fairly tried with my ^^th Tolles, of 1869, as they can be in 

 London, by as callable exj)ert8 as there are in London, and each one 

 shall report for this Journal. If Mr. Wenham declines that fair offer, 

 I will make another ; I will state what my objective has done. It has 

 resolved fairly the 19th band of Nobert's test jilate. I have seen it 

 (doubt if I could now, my eyes are four years older than then). Dr. 

 Woodward has made a fine, sharply-defined photograph of the Am- 

 phipleura pellucida with it ; that was before it went to London. Now 

 will Mr. Wenham state as explicitly what his twenty-year-old ith, and 

 any other objective that he has made since, not exceeding in power a 

 true y^jth, can do on those two tests ? When Mr. Wenham and Dr. 

 Pigott, Dr. Maddox, Mr. Mclntire, Dr. Woodward, and myself, all 

 agree about the " Podura scale," then I will accept that for a test 

 object, not before. 



I am glad that Mr. Wenham has defined his position, i. e. he 

 teaches workmen to make objectives. It seems as if he thought that 

 Mr. Tolles was such a workman, taught by some teacher. If that was 

 his impression, it was a mistake ; although he might teach, he never 

 has ; and now that his health is such that he has left for a warmer 

 climate to avoid our cold spring weather, not a first-class lens can be 

 made bearing his name, until he returns with restored health. 



It seems that Mr. Wenham is not the only one who has misunder- 

 stood that unfortunate glass. I find a reference to it in the annual 

 address of the President of the Royal Microscopical Society. " The 

 lens in this instance was properly corrected as a dry lens." How an 

 immersion lens that won't work well dry, could be i)roperly corrected 

 as a dry lens, is not comj^rehensible. " It may be quite jjossible that 

 if the lens had been readjusted, so as to give the best image for im- 

 mersion in balsam, a slightly greater angle might have been obtained ; 

 but this would not have been a fair way of making a comparison, as it 

 is not the mode in tvhich the «jlass would ever he employed in actual prac- 

 tice" Precisely what this meant I do not understand. The only way 

 that I ever heard of for adjusting a glass " in actual practice " is to 

 adjust it for the cover and object in view, — for maximum angular 

 aperture, to search for it. 



Believe me yours, &c., 



Charles Stoddee. 



* If Sir. Wenham •will himself bring the objectives, I can assure him a most 

 hearty, cordial, and friendly reception from the American microscopists who have 

 so long used and admired his ingenious contrivances for their favourite instrument. 

 I have shaken hands with him across the ocean for some time, now I shall be 

 happy to do so in person. We will not promise that we can teach him anything 

 about objectives, but will promise that we are willing to be taught. 



