758 



606 



182 



34 



108 Economy of Machinery and Manufactures. 



mentof soap or grease, was immediately enabled to move, without exerting a greater 

 effort, more than three times the weight he could before. " 



The advantage of mechanical assistance will appear from the 

 following experiment related by M. Redelet, sur VArt de Batir. 



" 1st. A block of squared stone, weight - - - 1°80 lbs. 



" 2nd. In order to drag this stone along the floor of the quarry, roughly 

 chiseled, it required a force equal to - 

 " 3rd. The same stone dragged over a floor of planks required - .652 



"4th. The same stone placed on a platform of wood and dragged over 



a floor of planks, required - - - 



"5th. After soaping the two surfaces of wood, which slid over each 



other, it required - - - - t - . - 



"6th. The same stone was now placed upon rollers of three inches 

 diameter, when it required to put it in motion, along the floor of the 

 quarry, --..-.--- 



"7th. To drag it by those rollers over a wooden floor, - - 28 



"8lh. When the stone was mounted on a wooden platform, and the 

 same rollers placed between that and a plank floor, it required - 22 



" From this experiment it results, that the force necessary to move a stone along 

 the roughly chiseled floor of its quarry, is nearly two thirds of its weight — to move 

 it along a wooden flocfr, three fifths; by wood upon wood, five ninths; if the wooden 

 surfaces are soaped, one sixth ; if rollers are used on the floor of the quarry, it re- 

 quires one thirty second part of its weight; if rolled over wood, one fortieth; and 

 if between wood, one fiftieth of its weight. 



The erection of palaces and temples,* monuments and tombs, 

 seems to have engaged the early attention of nations ; and the mode of 

 removing, from their native repositories, those immense blocks of stone 

 which minister to the grandeur or piety of the builders, has, through 

 ages, and to the present day, remained a subject of astonishment. 

 The manner of applying the different degrees of force necessary to 

 move those ponderous masses, and to elevate them to the summit of the 

 pyramids, or of the temple of Belus, is beyond the limit of conjecture ; 

 their artificers must have possessed mechanical knowledge, of which 

 their history contains no record. 



An interesting discovery, which was made by Champollion, a few 

 years since, in Egypt, of an aircient Egyptian drawing, may throw 

 some light upon this subject. " A multitude of men appeared har- 

 nessed to a huge block of stone, on the top of which stood a single 

 individual with his hands raised above his head, apparently in the act 

 of clapping them, for the purpose of insuring the exertion of their 

 combined force at the same moment of time." 



99 



See page 6 f Economy of Machinery and Manufactures. 



