xx. ABSTRACT OF PROCEEDINGS, 
NOTES AND EXHIBITS. 
1. Mr. Lawrence Harcrave exhibited some models and made 
a preliminary announcement of a discovery of importance to aerial 
navigation. He had, he intimated, made experiments that 
showed—(1) That the profile of a soaring bird’s wing, and pieces 
of metal of a somewhat similar curve, generated vortices on their 
concave surfaces when the chord of the curve made a negative 
angle with the direction of the wind. (2) That all the concave 
surfaces were in contact with air moving towards the mean direc- 
‘tion of the wind. (3) That the mean pressure on the concave 
‘surface was higher than that on the convex side. (4) That the 
chord of the curved metal might make a negative angle of ten 
degrees with the direction of the wind, and still havea higher 
pressure on the concave side than on the convex. The direct 
inference was, he said, that gravity could be entirely counter- 
acted by a volume of disturbed air moving in a horizontal direc- 
tion, and that flying machines of great weight could be held 
suspended in a horizontal wind, and rise vertically without the 
expenditure of any contained motor force. 
2. Mr. R. T. Baker exhibited specimens of “ Oliverian ” oil 
‘obtained from the bark of Cinnamomum Oliveri, Bail.—a species 
_of Cinnamomum he has recently recorded as new for this colony; 
and which has now been shown to extend over a large area of the 
coastal district from the Tweed River to the Illawarra. The per- 
centage of oil from the bark was nearly 1 %/, an excellent result. 
It is a light golden-coloured oil, with a specific gravity of 1° 00105, 
highly aromatic and persistent, contains cimnamic aldehyde, 
eugenol, together with other constituents. Its commercial possi 
bilities are favorable. Botanical specimens of the species and the 
fungus Melampsora nesodaphnes were also shown. 
The following donations were laid upon the table and acknow- 
TRANSACTIONS, JOURNALS, REPORTS, Ke. 
(The Names of the Donors are in Italics). 
Des ager oc ae Geological Survey. Annual Report, 1895, 
Vol. v The Survey 
