Thirty two pages about 5x7, very likely made in the seventies and almost certainly not later than that judging by the paper and quality of photostat. That it is a machine photocopy is verified by the ghost print seen on copy pages which came from a slight charge remaining on the drum in the earlier machines. What they copied this from was probably photo negatives of an original copy although I am not sure how that accounts for the illustration, I have never seen an original copy. Reference to this conceived aircraft is not uncommon due to the attempt of the "inventor" to sell his device to the Confederacy during the Civil War. It is not without some merit despite how plain it is to us today it would never work; the fellow being a dentist and not an engineer never worked out the figures for the weight and how much hydrogen was needed to displace that. There are some fanciful notions though that add to the novelty of interest including lever-accentuated beating wings to drive you through the air not unlike rowing a boat. In addition he proposes two other methods to power a piston machine to drive the wings, one being steam. Interesting and unusual item to say the least, either the concept or the history or this reprint booklet.