170 Transactions. — Miscellaneovs. 



such to be tlie case, we have a marked satisfaction in knowing that no part 

 of the colony is so favourably placed as we are in this respect, as in addition 

 to the companies now forming our volunteer force there are a large number 

 of men who have had to learn how to defend their homes in years gone by, 

 and these I feel sure could largely be counted on as a defence force at a few 

 hours' notice. If the enemy came by Eangitoto Channel they could only 

 land in the vicinity of the lake where Auckland would not be threatened, 

 and a capital defence of the isthmus of the North Shore could be made. 

 If, on the other hand, they came through the eastern passage, they would 

 probably push up the Tamaki and strike the Panmure road. With the 

 defence now to be made I have nothing to do, except to point out the 

 number of small steamers we have in the harbour which could carry a large 

 body of armed men to any point threatened within an hour. 



In conclusion, I do not lay claim to any original work except adapting 

 the ways already known to our harbour. In this also I have to acknowledge 

 with thanks much information from Captain Burgess, harbour master, and 

 for the plan of laying the torpedoes to A. H. Atteridge, in a paper to the 

 Fu/mlar Science Bedew, 1873. 



Art. XIV. — Experiments on the Lifting Power of Inclined Planes in Aerial 



Transit. By Henry Skey. 



Plate IV. 



[Bead before the Otago Institute, 9th October, 1877.] 



0-ME of the great difficulties in aeronautics is the steering the apparatus 



if a balloon be employed, and even if any other method of aerial transit be 



attempted the additional difficulty presents itself of rendering the apparatus 



stable in high winds. 



To steer a balloon does indeed appear a hopeless task ; but to the 

 question, is it possible that an aerial machine could be devised which 

 would retain its position of equilibrium in the fitful and uncertain currents 

 of tlie atmosphere, while at the same time it could be propelled at an 

 angle more or less against the wind, so that by tacking it could, like a ship, 

 navigate against the wind, it will be my endeavour in this and two following 

 papers, from observation, experiment, and demonstration to answer in the 

 affirmative. 



The whole animal kingdom, from mammals, birds, fishes, lizards, and 

 insects furnishes us with creatures more or less endowed with powers of 

 flight ; but it is more especially to the sailing flight of sea-bu'ds that our 

 attention will be at present directed. What must attract notice is their 



