MACHINERY. 439 



chines for card-setting, dye-engraving, and coining. Machines do 

 not create power ; but they serve as vehicles, or agents, by means 

 of which it is applied : and whatever is gained by them, in the in- 

 crease of pressure, or tension, is compensated for by the consequent 

 loss of velocity. Generally, machines are employed to transmit mo- 

 tion ; but in the case of presses, and in some other instances, their 

 object is merely to maintain a continued pressure, or tension. 



The simpler forms of machinery, known to the ancients, have 

 already been referred to under the branch of Mechanics ; and their 

 warlike machines will be reserved for the department of Machetech- 

 nics. Machines for grinding grain, were, doubtless, of very early 

 invention ; and the hand-mill is referred to in the New Testament. 

 The upper stone was, in later times, attached to a shaft, and turned 

 by oxen or asses. The invention of mills, has been ascribed to 

 Myles of Sparta, and to Pilumnus, one of the gods of Rome : but 

 they were certainly known, at an earlier period, to the oriental na- 

 tions. Water-mills, were invented about the time of Mithridates ; 

 near whose residence one was built : and floating water-mills, or 

 tide mills, were constructed by Belisarius, when the Goths stopped 

 the Roman aqueducts, A. D. 536. Wind-mills, are said to have 

 been invented in the time of Augustus; but they were first introduced 

 into central Europe, by the Crusaders, about the year 1100. Saw- 

 mills, are said to have existed in Germany as early as A. D. 350 ; 

 but more certain mention is made of them at Augsburgh, in 1322. 

 Paper-mills, are said to have been invented in the 14th century. 



The elastic power of steam, was known to Hero of Alexandria ; 

 who applied it to produce the rotation of a hollow sphere, about 120 

 B. C. The invention of the steam engine, has been ascribed to 

 Garay in Spain, in 1543 ; to Mathesius of Germany, in 1560; to 

 Branca of Italy, in 1629 ; to Solomon de Caus, of France, in 1615 ; 

 to the Marquis of Worcester, in 1663 ; and to Denis Papin of France, 

 in 1690 : but none of their inventions deserves the name of a steam 

 engine ; though they may have illustrated its principles. The first 

 available application of steam power, was made in 1698, by Savery of 

 England ; whose apparatus would more properly be called a steam 

 pump. It was not till 1705, that the first steam engine, properly so 

 called, was invented by Newcomen, a blacksmith of Dartmouth. It 

 was an atmospheric engine ; the pressure of steam indirectly raising 

 the piston, and the pressure of the atmosphere driving it down, when 

 the steam was condensed. 



Newcomen's engine was greatly improved by the addition of the 

 safety valve, invented by Papin ; and of the self-acting valve rods, con- 

 trived by Humphrey Potter; by which the engine was made to work 

 itself, while he found time to play. This engine suffered an enor- 

 mous waste of heat, by the cooling of the cylinder at each stroke ; to 

 remedy which was the object of James Watts's great improvement, 

 in using a separate condenser. This was invented in 1763, but pa- 

 tented in 1769, to Watt and Roebuck, afterwards Watt and Bolton. 

 By this invention, and by the application of the crank, to enable it to 

 produce rotary motion, the steam engine has become that powerful 

 agent in the arts which it is at the present day. The use of high 



