NOTES ON FLYING-MACHINES. 19 



the walls of this building as a memorial of our late esteemed 

 "Vice-President. 



And now, gentlemen, it only remains for me to thank you for 

 the indulgence which has been accorded to me in the performance 

 of the duties of President for the past year, and to express the 

 hope that the Royal Society may continue to nourish and increase 

 its usefulness under the auspices of your new President, Mr. 

 C. S. Wilkinson, who it is my privilege and pleasure now to 

 introduce to you. 



RECENT WORK ON FLYING-MACHINES. 

 By Lawrence Hargrave. 



[Read before the Royal Society of N.S.W., 1 June, 1887.'] 



Since communicating the paper "On a form of Flying-machine" 

 more efforts have been made to determine the relation between 

 the weight, area and power that is necessary for the successful 

 designing of large and similar structures. One power has been 

 adhered to throughout viz., 24 red elastic bands of the same 

 strength as those previously tested : the weight has been reduced 

 to 1*18 lbs., and the area varied in numberless ways, resulting in 

 the dimensions shewn in Fig. 7. B. & C. which are the best that 

 can be suggested for the power. Fig. 7 A., is the one previously 

 described. 



It is observed in B. and several earlier models that they do not 

 descend as the power is decreasing, but keep approximately 

 horizontal until the wings stop napping ; the cause is thought to 

 be that the power used at starting is excessive for the weight and 

 area, and that if the terminal power were to be maintained 

 throughout, a far greater distance would be passed over • and that 

 the superabundant power at the commencement of the flight is 

 expended in uselessly forcing the speed • therefore C has a fusee 

 winder. 



The absence of the head in C is a marked improvement, as any 

 reduction in the number of parts must be, and it was not discovered 

 without considerable labour. 



The centres of gravity and effort have both been brought further 

 forward, resulting in a much easier and more graceful motion of 

 the apparatus. 



The mean result of the three models is seen by the table to be 

 that 161*4 foot-pounds of energy propels a weight of 1*29 pounds 



