This page has not been proofread
19, Bloomsbury Street,
London. 20 June 1868
W. C.
Revd Sir,
I am this day in receipt of your letter of the 24th which I hasten to reply to
It would appear that you have been using the eyepiece as a Huyghenian or negative instead of as a Ramsden or positive - the latter (A) requiring to be drawn out something like 3 inches from where you
