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same screw for every given diameter, and any one will fit 
the other, the dies for producing them having been origi- 
nally copied from those of Whitworth in Manchester. He 
proposed to the great Railway Companies — The London and 
North Western, Midland, and Great Northern — that they 
should carefully determine the fewest possible number of 
sizes of engines and carriages that would suffice, and also how 
every single piece might have strictly defined dimensions, in 
order that greater economy might result from the smaller 
number of patterns and machines required in the construc- 
tion. He also suggested to architects and builders that the 
principal windows and doors of houses should be made in 
only three or four different sizes. By this means doors and 
windows could be manufactured without regard to any par- 
ticular builder or any special house and could be kept in 
stock, thus obtaining the best possible windows and doors 
at the least possible cost, and all fitting perfectly. 
He next invented his standard gauges and measuring 
machine capable of measuring lengths differing by so small 
an amount as one millionth of an inch. This degree of 
accuracy is due to the sense of touch, and is not obtained 
by that of sight. The council of the Society of Arts awarded 
him the Albert Gold Medal “ for the invention and manu- 
facture of instruments of measurement and uniform 
standards, by which the production of machinery has been 
brought to a degree of perfection hitherto unapproached, 
to the advancement of arts, manufactures, and commerce.” 
In 1842 he invented a simple machine for sweeping the 
streets, which was adopted by the authorities in Manchester. 
It did the work of about thirty men. 
Of his various improvements in machine tools, including 
his duplex lathe, planing, drilling, slotting, shaping, and other 
machines, we cannot give details; but all his inventions 
were displayed at the Great Exhibition of 1851, and the 
reports of the juries were very complimentary. They say 
