Newsletter 8

Newsletter 8

7th April 2023

At the Dunedin Winter show of 1910 people could, for a special fee, see something they had not seen before - an aeroplane built in their city. It was the culmination of seven years of experimentation and construction by John Henry Gill, a professional photographer living in Musselburgh. The Winter Show fees amount to 280 pounds.

The "Lyttelton Times" was able to provide some technical details of Mr Gill's machine:

"His machine bears a general resemblance to the Bleriot type, but it carries four devices which are not in use on any other flying machine in the world. The first of these is an air-sac under the body of the machine, which is filled from the exhaust of the engine. One purpose of this is to form a float should the machine drop suddenly to earth, though this latter contingency is rendered practically impossible by two other devices, of which more later. But the inflated sac is not only a precautionary measure, it is also a help to buoyancy, since it will lift 701b of the total weight of the machine. That weight, by the way, is but 4601b. though the machine is 36ft long and 31ft from wing to wing. 

The second patent has an object similar to the first, and is one for which long and unsuccessful search has been made by aviators. The problem was to be able instantly to check the dip of a monoplane should the engine fail suddenly. Tightly rolled on the margins of the wing frames of Mr Gill’s monoplane are cloth blinds, and in case of a sudden failure of the engine, the pilot has only to touch a lever, and in the same instant 190 square feet of cloth cover the frame of the wings, and not only prevent a sudden drop, but also prevent a capsize, acting, in fact, as lateral supports like those on the Samoan canoes. 

In the bows is another device, a curved frame, also fitted with cloth blinds, which when stretched across the frame (as they can be in a second when the aviator presses a pedal with his foot) prevent the monoplane from taking a header. This patent is termed a curvative elevator, and is the only thing of its kind on any aerial machine. 

The aviator steers by means of a triangular rudder in the bows, but in case a right angle turn is desired he can accomplish this by means of two appliances known as arenoids, which are fitted on the extreme end of the wings. By means of these Mr Gill claims that he can run broadside on to the wind, and not only head to the wind or with the wind, as is compulsory with other monoplanes. The engine is a model of bulkless power. It is only 14m long and 18in high, and generates 24-30 h.p. A marine engine of one-sixth the power would occupy twice the space and weigh twice as heavy. In theory, to sum up, Mr Gill has apparently overcome many difficulties that have not previously been successfully met by aviators."

This writer has a little knowledge of early aeronautics and, with the hindsight of historical knowledge, can make a few comments of Gill's design.

The inflated sac, filled with exhaust fumes and preventing accidental sinking, is a good idea, though an image which seems to have been part of a patent application shows a boxy fuselage which must have added to the drag of the machine - though that might not have been significant given the slow speed which was anticipated. Similar flotation devices were standard on carrier-borne planes in the 1920s.

The tightly rolled cloth blinds which were ready at a moment to enlarge the surface area of the wings are not too well described in the "Times" but seem to be like a parachute. This concept has been applied in recent decades to light planes and gliders and has saved lives - I have met a man who claimed his father was saved by one in a glider collision, otherwise he would not have been born.

The "curvative elevator" also sounds like a good design feature, producing a rapid change in the centre of lift of the plane and possibly doing exactly what Henry Gill hoped it would. He had certainly experimented with his design in model form and presumably had confidence in its effectiveness.

The "arenoids" on the wings are what we today would call ailerons which were becoming standard on aeroplanes by 1910.

In June of 1910 Henry Gill made a private flight test of his plane at Andersons Bay. It flew for 900 yards and attained a height of 160 feet. In attempting a turn, the structure became overstressed and failed, causing a crash requiring repairs which took a few weeks.  

On August 6th, 1910, a public flight was attempted. A small crowd gathered near the Pelichet Bay cement works at 10am and watched for four hours while the machine was assembled. Then flight was attempted but the engine didn't develop its full power so a few runs over the ground were all that people saw.

A further attempt was made on the 21st, but the engine began to break its mounting and had to be switched off. Again an attempt was made at the end of the month, on the beach between St Kilda and St Clair but the chosen take-off area had become a small lagoon due to recent seas. An attempt was made nearby but the soft sand made takeoff impossible.

Not long after, the Gill Aerial Syndicate met and decided to end its financial support of the machine. Its cost was L700, which amounts to $140,000 today. Henry John Gill went back to photography and died in 1932.  His grave can be found in Dunedin's Northern Cemetery.