Austrian engineer and piano builder Wilhelm Kress began his aeronautical study and research with large models, beginning in 1877. His research was significant enough that he was invited to lecture before the Vienna Engineering Society in 1892. As part of his presentation he flew a rubber band powered large model (which he called an "Aeroveloce") which featured two of Kress' "elastic" air screws. From that design he developed the Kress Aeroplane shown below, which was to have a combined wing surface area of 732 square feet, and two contra-rotating propellers, each 10 feet in diameter. Kress developed a propeller of considerable efficiency which was flexible enough to form its own shape, akin to that of an auger, when under a load.
By 1893 Kress had designed a large "Wing-Flapping Flying Machine," as shown below. The wings were to have a total surface area of 904 square feet and the "car" (fuselage) was to be 32 feet long. As the wings flapped, the angle of incidence was to change, with the greatest postive angle of incidence (3 degrees) on the upstroke. When Kress' papers were published in the July 1894 isssue of "Aeronautics," Octave Chanute posted an addendum which observed that Kress' estimates "... of power required are entirely inadequate."
Between 1900 and 1901 Kress designed and built one of the most interesting of the pre-Wright aeroplanes. His machine was designed to be tested on water, for he thought that any potential damage in case of an accident would thus be limited. Kress' Waterborne Aeroplane was a step-winged three-surface monoplane with a large horizontal tail and large rudders. The flying machine's floats were well-designed but lacked a "step," and so it would have been difficult, if not impossible, for the machine to lift from the surface of the Tullnerbacher reservoir, where the trials were conducted in October of 1901. Also, the 30 h.p. Daimler gasoline engine, which drove two very large contra-rotating cloth-covered propellers, was inadequate for the task of lifting the massive machine.
As can be seen in the above schematic, the Kress Waterborne Aeroplane was very well-built, and, by all appearances, very strong. The machine had plenty of potential lift, as the curved wings were set at a fair angle of incidence. Kress had hoped to utilize a more powerful engine but, it's said, the expense of construction and the unavailability of an engine of the proper weight and power led Kress to use a less expensive, immediately available but considerably less powerful Daimler engine.
The series of trials conducted in October of 1901 were not a success. While the aeroplane demonstrated that it could generate tremendous lift, it never left the water. It seems that Wilhelm Kress ended his aeronautical experiments with this machine. Many have expressed the thought that had the Kress machine been adequately powered and had the floats been equipped with a "step" to break the adhesion of the water's surface, the great machine may have flown. The Kress Waterborne Aeroplane was one of the most promising machines built in the years preceding the Wrights' successful 1903 Flyer.