OBITUAHY NOTICES. 
383 
could sound the depths of his knowledge. Association with 
him was a pleasure I can only look back upon, but the lessons 
taught me in his experience are treasures to be ever remem¬ 
bered. 
In electrotyping, Mr. Chapman essayed a new role, but his 
studies in electricity and practical experience with its appli¬ 
cation in other branches equipped him, with very brief in¬ 
structions, to undertake the work and carry it on most suc¬ 
cessfully. I need not enter upon the difficulties he overcame, 
nor the experiments he conducted while obtaining a mastery 
of the subject, interesting and creditable as they were; let it 
suffice that in the end he secured an average increase in de¬ 
posit of reguline copper of over 30 per cent, with the same 
consumption of fuel—in this case the zinc battery plates— 
and at times almost reached the maximum deposit to be ob¬ 
tained with a perfect plant. As photographer he had only to 
adapt his knowledge to a new class of work, but, learning the 
requisite conditions, he was not satisfied until he had filled 
them and could furnish photographic prints for the engraver’s 
use on the exact scale proposed for the engraving. His marked 
ability as a mechanic helped him in this, as in other work, 
having devised and constructed a machine for adjusting to 
true scale prints of negatives from a distorted drawing; but 
his reputation as a photographer was made long before his 
entry upon the Survey—a reputation that has been cordially 
expressed in a recent number of the Photographic Times , and 
to which I am indebted for some of the facts of his life re¬ 
ferred to in this paper. 
Mr. Chapman was elected a member of the Philosophical 
Society December 22,1888. He was a constant attendant at 
the meetings, contributed to the discussions, and evinced a 
laudable interest in the welfare of the Society. He was a life 
member of the Polytechnic Club of the American Institute of 
New York City and a member of the National Geographic 
Society. 
If our success in life is measured by the warmth of the 
friendships we leave behind us, or by the record of the work 
55-Bull. Phil. Soe., Wash., Vol. 13. 
