Tue Conductors of the Philosophical Magazine have to acknowledge the editorial 
assistance rendered them by their friend Mr. Enwarv W. Braytry, F.L.S. 
F.G.S., Assoc. Inst. C. E.; Member of the American Philosophical Society, 
and Corresponding Member of the Philosophical Society of Basle, &c. Librarian 
to the London Institution. 
