FLYING-MACHINE MOTORS AND CELLULAR KITES, 75 
The conclusion therefore, which this paper maintains is, that, 
generally, considerable cheapening of branch line construction 
can be made by lessening requirements and by improved locomo- 
tive design ; but that there is a limit, beyond which any consider- 
able cheapening in capital expenditure will be more than over- 
balanced by excessive working expenses. An attempt has been 
also made to indicate what that limit is, as far as can be done, 
without having the ever varying circumstances of each particular 
project in view. In conclusion, the author would add that he 
presents this paper with the full concurrence of the Engineer-in- 
Chief for Railways, who however is not necessarily in agreement 
with it in every particular. 
FLYING-MACHINE MOTORS AND CELLULAR KITES. 
By Lawrence HarRGRAVE. 
[With Plates I.—IV.] 
[Read before the Royal Society of N. S. Wales, June 7, 1893. | 
No. 18 Engine (Plate 1.)is the second steam motor for a flying- 
machine made by the writer. Its total weight without spirits, 
water, or body plane, is five pounds eleven ounces. This weight 
includes six feet nine inches of one and a-half inch by one-quarter 
inch redwood forming the strut for the body plane. 
Eleven different burners have been tried. The most reliable 
arrangement is to put all the spirit on at once. The flame is 
steadier than that of No. 17, in consequence of the spirit being 
heated by its own flame before it has passed between some of the 
turns of the water boiler. The flame striking the water boiler 
first has a tendency to vary the supply of heat to the spirit holder. 
Some of the first burners were supplied with spirit by a feed pump. 
