Based on Watson's rocking wing patent, it is assumed that his first powered machine was completed between early to mid 1909 since it is almost exactly like the illustration that accompanies the patent. The Watson No.1 was of reverse sesquiplane layout, with the upper wing being approximately one half the span of the lower wing. The main wings were in two separate sections, between which the pilot sat. He had no instrumentation of any sort. The upper wing was mounted at the apex of an 'A' frame, with the main wing forming the cross bar of the 'A' and with long skis being fitted at its base.
The wings were of simple rectangular planform; being of equal chord, the lower was braced by wire from the apex of the 'A' frame and from its base. There was considerable camber applied to the main wings and upper surface. Two small skids were fitted at the leading edges of the wingtips, but unusually the starboard wingtip skid was longer than that on the port wingtip, curving upwards at a greater angle.
There was no fuselage as such, the boxkite tailplane being positioned behind the 'A' frame by bracing spars. The entire tail section pivoted, providing pitch, which was interconnected to an actuating column positioned below the upper wing. There was no moveable vertical tail, although the tailplane was fitted with end plates. Powered by a four cylinder 40 hp Dutheil Chalmers engine, the No.1's unusually configured powerplant was fitted in a rectangular frame ahead of and slightly above the main wing.
Dimensionally the aircraft was approximately eight feet to the top of the rocking wing, nearly fifteen feet from the tips of the skids to the rear of the boxkite tail, with a wingspan of approximately 20 feet. It was primarily constructed of bamboo bound with, according to a newspaper article (The Scotsman Weekend Magazine, Saturday July 16 1961), "...Scotch tape, the wooden members being clamped together by light metal clips." Only the wing and tailplane surfaces were covered in fabric. The aircraft's overall finish was somewhat rough and ready.
A line drawing of Watson's No.1 that appeared in the February 1954 issue of Aeronautics magazine illustrating its general configuration, although the location of the engine is incorrect. Philip Jarrett
There are rumours that Watson acquired his first aircraft's engine from Paris domiciled Brazilian aviator Alberto Santos Dumont. This was a four-cylinder horizontally opposed Dutheil Chalmers . in small numbers by Dutheil Chalmers & Cie 81 - 83 Avenue D'Italie, Paris, France, the powerplant that was fitted to Watson's No.1 aeroplane was of unusual layout, the propeller was mounted betweentwo horizontally opposed banks of cylinders. Weighing 164 lbs, the water-cooled Dutheil Chalmers rated at 1,200 rpm, with a bore and stroke of 133 by 135 mm.
A small conical fuel tank was fitted above the engine between the uprights that formed the apex of the 'A' frame ahead of the rocking wing. Fuel flow to the engine was most likely via gravity feed. According to James Watson, ten propellers were made for the No.1 by Kerr Sturrock, Joiners, Dundee, but each successive one was, "...smashed by the revolutions of this little engine before a propeller was designed and made of a suitable pitch and length."
Although in many respects conventional aeroplanes of the day that borrowed from existing sources; boxkite tail surfaces - in fashion in Europe at the time, skids instead of wheels - a Wright influence, Watson's machines incorporated a totally original means of lateral control: the rocking wing.
Watson's idea was to provide control about the longitudinal axis in one moveable surface - the parasol wing mounted above the mainplane that was actuated by a single lever, which also moved the elevator, thereby dispensing with the need for a number of different controls in the cockpit.
Read about rocking wings here
Watson's first aeroplane was fitted with a skid undercarriage, which corresponds with stories that he adopted an assisted take-off device similar in principle to that which the Wrights invented whilst flying the 1904 Flyer at Huffman Prairie. Although instead of the aeroplane sitting on a rail, and a tower from which a weight was suspended, Watson supposedly laid down planks on the ground and lubricated them; the weight, which would drop, providing momentum for the machine was suspended from a tree branch. A description of how it worked appeared in the June 1957 of Meccano Magazine, although the article described the means with which Watson's supposed 1903 glider became airborne;
"[The aircraft] sat in a wooden cradle or on skids, which could slide freely on planks lubricated with lard or graphite. A rope hooked under the glider led forward to a pulley, then back under the plane, round another pulley and finally up and over the branch of a tall tree. On the end of this rope hung two 56 lb. weights and an anvil borrowed from a nearby smithy."
An illustration of the rear of a four cylinder horizontally opposed 1909 Dutheil Chalmers engine on display at the Paris Air Salon that year. Flight via the National Museums of Scotland
Despite the fitting of the Dutheil Chalmers engine and Kerr Sturrock's propellers, Preston Watson's No.1 aeroplane remained firmly earthbound, and he placed it in store in a shed on the property of Mr James Bell at Rossie, Forgandenney, about 25 miles west of Dundee. A year later Watson gave the forlorn craft away to a group of local enthusiasts from the Dundee Model Aero Club, founded in November 1909. David Urquhart, the founder of the Dundee Model Aero Club and two friends, David Robertson and William Gibb, recounted in 1961 how the Dutheil Chalmers motor was removed and the aeroplane was converted into a glider in the club house used by the modellers.
A local newspaper, the Dundee City Echo (November 1910, No.45) recorded that the Dundee Model Aero Club was, "....successful in securing the support of a well-known gentleman in Dundee who has been experimenting for some time with a machine of his own design and construction, and he has kindly offered us one of his aeroplanes with which to make experiments." Accompanying the article was a caricature of David Urquhart holding a model aeroplane, its resemblance to Watson's rocking wing aeroplanes is particularly noteworthy.
When finished, the glider differed little from its original form, with the exception of a modified undercarriage, comprising two wheels attached to an axle and probably sprung with bungee cord. These were attached to the rear of the long curved skids. The four uprights that held the engine in place and the foremost 'A' frame bracing struts between which the conical fuel tank was located were removed from in front of the wing, but little else appears to have been changed on the aircraft.
Unusually the port wingtip skid is absent in an existing photograph of the glider in its modified form, taken with an individual in a semi reclined position in the pilot's seat holding the single control lever that hung below the rocking wing.
By June 1911 the glider had been completed and several flights had been made from a rise on the property of a Mr Geo. Ballingall of Newton, Warmit, in Fife. Within five months however, the keen members of the Dundee Model Aero Club were constructing a new glider. What they did with the earlier one is not known; there are some in the Dundee area that believe that it still lies undisturbed in a shed somewhere waiting to be rediscovered.
Next, read about Preston Watson's second aeroplane here