OF ARTS AND SCIENCES : FEBRUARY 26, 1867. 247 



sons with you, and in the course of nature after you, may prolong and 

 enhance the reputation of the estabhshment at Cambridge port, so that 

 in future years it may contribute largely, as it now does, to the honor 

 of the country and the advancement of astronomical research. 



Mr. Clark responded in the following remarks : — 



Mr. President and Gentlemen of the Academy : — 



I know not how I can better express my gratitude for these honors, 

 than by giving some brief account of the manner in which my efforts 

 as a working optician were commenced and have been carried on. 



Up to 1844, and when more than forty years of age, I had never 

 witnessed or attempted the grinding of a lens of any description. My 

 elder son, George B. Clark, then a youth of seventeen, during a school 

 vacation, sought amusement in casting and grinding small reflectors for 

 telescopes ; and without any thought or design beyond assisting him to 

 find interest and instruction in his pastime, I joined him. 



After working, and talking with astronomical friends, and consulting 

 books, until we found that reflectors, even when wrought with utmost 

 skill, were little sought for, I proposed to the youth to try a refractor ; 

 but he objected by saying, " The books represent it as a very difficult 

 thing." 



Materials were however procured, and the attempt made, with such 

 results as to induce a repetition, and finally another, until it became a 

 settled occupation for us both. Thus it began, as boys' play, and so 

 far as my own spirits and feelings have been affected by it, it has been 

 boys' play all through. So I cannot appeal to your sympathies by any 

 gloomy tale of disappointment or privation. 



Hope and courage have been well sustained, and though my circum- 

 stances were such that I could not go far, unless purchasers for my 

 lenses could be found, I was fortunately soon able to give them a char- 

 acter which insured their sale. 



There exists among the double stars such a variety, in distances and 

 magnitudes, that tests for the excellence of telescopes of different di- 

 mensions are always at hand ; and through them the value of a glass 

 can be made known, pretty accurately, to a distant correspondent, who 

 has had experience, and is well versed in such matters. 



The evidence must, of course, have more weight if the stars selected 

 had never found a place in Struve's or any other catalogues, and were 

 of a character making very sharp defining necessary to exhibit them. 



