PRINTING ON OPAL GLASS.

TO the EDITORS.

GENTLEMEN,--Mr. Eyres, Messrs. Helsby's assistant, has taken upon himself to point out what he considers are errors in my article, at page 484, on Printing on Opal Glass.

I desire to reiterate that the process there mentioned is that employed to produce the results named, perchance with the occasional modification of manipulative details.

The writer denies that the glass employed is "patent plate opal," or that any credit should be given to Mr. Forrest for its introduction. I cannot see what Caesar has to do with the matter, for most photographers have known Mr. Forrest's name in connection with opal glass for many years prior to the introduction of Messrs. Helsby's process, and I am quite certain Mr. Forrest is the most likely person to know what should be the correct name of the article. It was he who styled it "patent plate opal." To call it "polished enamel" is simply absurd.

Mr. Eyres would do well to refer again to Mr. Helsby respecting his assertion that his patented pictures are adapted for viewing by reflection, and as transparencies. Probably his memory may come to his assistance.

That anything "ungentlemanly" was intended in my article I emphatically deny. Neither did I wish to take to myself the credit of introducing the "better way" of mounting mentioned; for many persons may doubtless have seen the thing done long before it received the unpronounceable designation of "Helioaristotypia."

Want of time precludes my pursuing this useless controversy further; and therefore I cannot reply to any future communications on this subject.-I am, yours, &c.,

GEORGE F. WILLIAMS.
Liverpool, 20th December, 1864.