I may mention among such experiments that not being able to get a lens of aperture enough to suit me, I tried a reflecting mirror or rather a reflecting telescope belonging to that college, and I presume, is there still. It was a Gregorian one, the mirror from four to five inches aperture and perhaps 3 1/2 feet focus. I speak from recollection not having seen it for nearly twenty years. My plan was to protect the small mirror from injury by putting in front of it a piece of a cigar box the size of a cent, on which the bromine sensitive paper was fastened. I expected to be able to focus by looking through the hole in the great mirror and moving the little one by hand, but on trial found it unmanageable and not answering so well as the common refracting camera.