WELLNER'S SAIL -WHEEL FLYING MACHINE. 63. 



flying macliines for their support in the air are in Prof. Wellner's 

 invention changed to a rotary motion. This construction, while 

 permitting of an easy, slow ascent, assures the horizontal position 

 and constant stability of the air-ship, at the same time permitting 

 of a high velocity. The more the latter is increased, the stronger 

 is the lifting power developed. The direction is given by a rud- 

 der at the end of the ship or by increasing the velocity of the sail- 

 wheels on one side only. It is the peculiar quality of these 

 wheels that they do not, as might be supposed, disperse the air 

 around them ; they rather attract it toward their rapidly moving 

 surfaces, condensing it to a powerful stream, which passes down 

 obliquely through their cylinders. Their velocity can be made 

 to surpass by far that of railway trains, thus enabling them to 

 conquer contrary winds and air currents. This flying machine 



Fig. 5. Wellner's Sail-wheel Flying Machine for Two Persons. 



will hardly be called upon to rise above the cloud region ; it will 

 be most efiicient to reach its goal on the shortest air line at a mod- 

 erate height above the earth. 



Fig. 5 shows a small sail-wheel air-ship for two aeronauts. 

 Each of the two wheels has a diameter of 477 metres and six 

 planes five metres wide. Two steam engines of twenty horse 

 power each are said to produce during one hundred and eighty 

 rotations per minute a velocity of forty-five metres, a soaring 

 speed of fifteen metres per second, and a carrying power of fif- 

 teen hundred kilogrammes. 



A larger machine (Fig. 6), comprising six sail-wheels of G'4 

 metres diameter and a steam motor representing eighty horse 

 power, will, at one hundred and thirty-five rotations, carry sixty- 

 four hundred kilogrammes and accommodate eight persons. 



