1820.] Mr. Gill on the Patent Self -existing Engine. 373 



Article VIII. 



Letter from Mr. Thomas Gill, Chairman of the Committee of 

 Mechanics in the Society for the Encouragement of Arts, &^c. ^c, 

 of London, to Prof. Thomson, on a pretended Self-moving 

 Engine. 



Patent Agency Office, No. 125, Strand, London, 

 SIR, Oct. 4, 1820, 



My attention has been lately directed to a gross imposition 

 upon the public in a pretended self-moving engine, which is now 

 exhibiting in this metropolis, and which 1 think it highly proper 

 to expose ; and thereby, as far as lies in my power, prevent the 

 delusion from being continued. 



It is announced in the following hand-bill : 



" The newly-discovered Patent Self-existing Engine for pro- 

 pelling ships at sea, carriages on the road, and all kinds of 

 machinery, without the aid of horse, steam, water, or other 

 power, now in use. To be seen at work, every day, Sundays 

 excepted, from ten in the morning till six at night, at JVo. 32, 

 Burlington Arcade, Piccadilly. Admittance, Two Shillings. 



" N.B. Gentlemen intending to have their machinery driven 

 by the above power are desired to apply as above, if by letter, 

 postpaid." 



I found the machine to consist of a light brass wheel, about 

 two feet in diameter, turning upon an horizontal axis, which is 

 supported at each end in square blocks upon the tops of two 

 brass columns, which are affixed to a mahogany table mounted 

 upon a thick pillar of the same wood, with feet and rolling cas- 

 tors, so that it may be moved about, and thereby show that it 

 has no communication through the floor of the room it is exhi- 

 bited in. The thickness of the table is about an inch and a half, 

 and the pillar is about six inches in diameter. Around the peri- 

 phery of the wheel are fixed at equal distances by screws a 

 number of small cylindrical rods or bars of metal which are 

 placed parallel to the axis of the wheel ; and at one end of the 

 frame surrounding the wheel (and which frame is besides sup- 

 ported on two other brass columns) is a brass pillar, which has 

 an arm or bracket, on which is fixed near the periphery of the 

 wheel a ball, which the inventor pretends is formed of a new 

 combination of metals, the composition of which he keeps a 

 profound secret, and which, he says, possesses a new species 

 of attraction, which is not magnetical, for the metal bars on the 

 periphery of the wheel so as to draw each of them in succession 

 continually towards it ; but as this attraction takes place equally 

 above and below the ball, he says that he cuts it ofl" below by 

 means of a plate of a different composition of metals, which is 

 placed beneath the ball, and thus he pretends that the wheel is 

 continually turned round by this new attempt at reviving the long 



