ON THE HISTORY OF HYDRAULICS, &c. 275 



[the piston rods move backwards and forwards three or four times in a 

 'second, and therefore, that each of the cylinders he filled and emptied six 

 or eight times in the same interval ; it is evident that the utmost accuracy 

 of workmanship is requisite, not merely to prevent useless expenditure of 

 fuel, but even to keep the machine in action at this speed at all.] 



For further information on the Steam Engine, consult Partington's History and 

 Description of the Steam Engine, 1822. Stuart's Descriptive History of do. 1824. 

 Historical and Descriptive Anecdotes of Steam Engines and their Inventors, 2 vols. 

 12mo, 1829. Farey on the Steam Engine, 4to, 1827. Gilbert, Progressive Improve- 

 ment^ on the Efficiency of Steam Engines in Cornwall, Ph. Tr. 1830. Coriolis, 

 Journal de 1'Ecole Polytechnique, vol. 13. Brewster's Journal, Nos. 17 and 19. 

 Birkbeck and Aldcock on the Steam Engine. Renwick on do. New York, 1830. 

 Tredgold on do. a new edition by Woolhouse, 2 vols. 4to, 1838, with various subse- 

 quent appendices. De Pambour on the Theory of do. Lardner on do. 7th edition, 

 1840. Russel on do. from Encyc. Brit. The last four treatises contain all that 

 could be desired on this subject. 



On its Applications, see Jonathan Hulls' Description of a New Machine, 1737. 

 Buchanan on Steam Navigation, Glasgow, 1816. Dodd on do. 1816. Wood's 

 Practical Treatise on Railways. Marestier, Mem. sur les Bateaux a Vapeur, 1824. 

 Cleland's Hist. Account of the Steam Engine, and its Application to propelling 

 Vessels, 1825. Seguin, Mem. sur la Navigation a Vapeur, 1828. Brees's Railway 

 Practice, 1838. 



LECT. XXIX. ADDITIONAL AUTHORITIES. 



Air Pumps, Condensers, 8fc. Boyle on the Spring and Weight of the Air, 4to, 

 Oxf. 1663, and Opera, passim. Varignon on an Air Pump, Hist, et Mem. de Paris, 

 x. 285. Leupolds Beschreibung der Luftpumpe, 4to, Leipz. 1710-12. Nollet, Hist, 

 et Mem. 1740, pp. 385, 567 ; 1741, p. 338, H. 145. Lowitz iiber die Eigenschaf- 

 ten derLuft, 1754. Coulomb on Condensing with an Air Pump, Roz. Journ. xvii. 

 301. Ingenhousz Vermischte Schriften, p. 197. Hindenburg de Antlia Baaderiana, 

 4to, Leipz. 1787. De Antlia Nova, 4to, Leipz. 1789. Goth. Mag. v. II. 81. 

 Prince's Air Pump, Trans, of the American Academy, vi. 235. Van Marum's 

 Simple Air Pump, Gilb. Jour. i. 379. Mackenzie's Air Pump, Nich. Jour. ii. 28. 



LECTURE XXX. 



ON THE HISTORY OF HYDRAULICS AND PNEUMATICS. 



NOTWITHSTANDING a few observations and experiments made by 

 Aristotle and his predecessors, the properties of fluids had scarcely been 

 the subjects of much accurate investigation before the time of Archimedes. 

 The progress which the science of hydrostatics in particular made under 

 this eminent mathematician, does the highest honour to his genius and 

 penetration. His treatise on floating bodies, although the theorems which 

 it contains are not so general as they have been rendered since the late 

 improvements in the methods of calculation, still affords us instances of 

 very ingenious determinations of the equilibrium of floating bodies of 

 different forms, grounded on the true principles of the opposition of the 

 general directions of the weight of the body and of the pressure of the 

 fluid ; and in this manner he has shown in what cases the equilibrium of 



T 2 



