246 Remarks on the History of Inventions. /> 



of tiie wedge and of rollers would be equally obvious, lu navigating his 

 canoe the princi|)le of the lever is again exemplified, in the action of his 

 paddles; and the simplest tackle for raising his mast, or hoisting his sail, 

 must present fresh instances of the same kind, as also of the principle of 

 the pulley. It is cpiite unnecessary to quote from Homer the process of 

 launching a vessel : 



Mox^oiaiv d'apa rifvyt Kartipvcnv tia aXa ciav : 



'• With levers then he launched it in the main." — Od. E. 261. 



Aristotle, among his multifarious works, has left a short treatise on me- 

 chanics : he describes the lever employed, as a steel-yard, CvyoQ, or as a 

 pole, yioyXoQ, the wedge, a^r]v, the inclined plane, pofxjjoc, and pulleys, 

 T-pv^iXoiai. He refers their efficacy generally to the same principle as the 

 lever, which he explains as depending on the greater proximity of the 

 shorter than the longer arm to the centre of motion, and the consequent 

 small size of the circle described by the former, as compared with the 

 latter. He also speaks of a combination of these powers, employed by 

 architects to raise great weights.* A little later, Archimedes composed a 

 treatise of far superior merit, on the same subject ; in this he has scienti- 

 fically discussed the state of equilibrium in all these instances, and exhibits 

 the practical skill of a modern engineer. 



I am persuaded we shall find much earlier traces of a systematic use of 

 the mechanical powers, in consulting the Egyptian remains. The archi- 

 tects who could construct the stupendous masses of the pyramids, must 

 have been far advanced in mechanical skill. It would be interesting to 

 turn over, with this view, the recent splendid publications, English and 

 continental, in which are engraved such a vast number of the paintings 

 decorating the sepulchral chambers of this extraordinary people j who, by 

 thus pourtraying all their ancient manners, have made the abodes of death 

 perpetuate the arts and habits of life for three thousand years. The pre- 

 sent wiiter has no opportunity of consulting these volumes himself, but he 

 mentions the subject, in the hope that some other correspondent of this 

 journal, more favourably situated, may be led to do so, and communicate 

 the result in some future number. 



Besides increasing his own powers by mechanical instruments, man also 

 presses into his service the strength of other animals, and even the forces 

 of the natural elements. 



The domestication of animals, for various purposes, is recorded among 

 the earliest occupations of our race : in such consisted the wealth of Abra- 

 ham and of Lot; and, as we find camels (those ships of the desert) included 

 in the list, we cannot doubt but that the transport of men and burthens 



* It is amusing in this mechanical treatise of Aristotle, to find two chapters de- 

 voted to the discussion of the grave questions, why dentists extract teeth most easily 

 with their forceps, and why men employ nut-crackers to crack nuts. 



