170 Transactions.— Miscellaneous. 
such to be the 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 Rangitoto 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 
Popular Science Review, 1873. 
Art, XIV.— Experiments on the Lifting Power of Inclined Planes in Aerial 
Transit, By Henry Sxry. 
Plate IV. 
[Read before the Otago Institute, 9th October, 1877.] 
One 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 the 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 
tive. 
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-birds that our 
attention will be at present directed. What must attract notice is their 
