4*5 proceedings. 



Exhibit. 



Mr. Lawrence Hargrave exhibited a compressed air engine 

 for driving a flying-machine, describing it as follows : — the 

 cylinder is If inches diameter and the stroke is 2 inches : 

 the engine weighs 2 lbs 7 oz. The receiver for the compressed 

 air is *21 cubic feet capacity, made of -£$ inch steel, single 

 rivetted, and brazed : the bursting pressure is about 900 lbs 

 per square inch : the working pressure will be 500 lbs per 

 square inch, and the reduced pressure lOOBbs per square inch ; 

 and there will be 9,200 foot-pounds available for work : this 

 power will have to be expended in from half to three-quarters 

 of a minute. The charged receiver weighs 6Ibs 12 ozs. A small 

 Richard's indicator has been made for adjusting the piston valve. 

 The wood and paper work will weigh about 2 lbs. The machine 

 is intended for a flight of 200 yards. As it will be some time 

 before the whole of the apparatus is in a condition to offer to this 

 Society in the form of a paper, anyone wishing to assist in the 

 development of artificial flight may have a tracing of the working 

 drawing now, and make sketches of the deviations : and from these 

 a double sized machine could be made introducing more steel and 

 less brass, and using triple expansion with a receiver pressure of 

 1,500 lbs, and a factor of safety of 2. I am indebted to Mr. James 

 Richard Thomson for much information that has been of great 

 assistance to me. 



The following donations received since the last meeting were 

 laid upon the table : — 



List op Donations Received since December 7th, 1887. 



(The Names of the Donors are in Italics.) 



TEANSACTIONS, JOUENALS, EEPOETS, &c. 



Aberdeen — University. Catalogue of the General Library, 

 Vols. i. and ii., and Supplement 1873 — 87. Cata- 

 logue of the Library, Vol. iii., Law Medicine, 

 1874. The University. 



Adelaide — Forest Flora of South Australia, Part 8. 



Government Printer, 8. A. 

 Eoyal Society, Transactions of the Intercolonial Medical 

 Congress of Australasia, First Session held in 

 Adelaide, S.A., August to September, 1887. The Society. 



University. The Adelaide University Calendar for the 



Academical Year 18S8. The University. 



Agram— Societe Archeologique. Viestnik hrvatskoga Arkeo- 

 logickoga Druztva, Godina ix., Br. 4, 1887 ; x., 

 Br. 1, 1888. The Society. 



Amsterdam — Revue Coloniale Internationale, Tome v., Nos. 



5 and 6, November and December, 1887. The Editors. 



