Supplement to Spons dictionary of engineering, civil, mechanical, military, and naval (1879) (14781506941)

Identifier: supplementtospon02spon (find matches)

Title: Supplement to Spons dictionary of engineering, civil, mechanical, military, and naval

Year: 1879 (1870s)

Authors: Spon, Edward Byrne, Oliver Spon, Ernest Spon, Francis N

Subjects: Engineering

Publisher: London, New York, E. & F.N. Spon

Contributing Library: Smithsonian Libraries

Digitizing Sponsor: Smithsonian Libraries

Text Appearing Before Image:

h it would not affect the accuracy of the test,might seem objectionable to those whose engines were subjected to it, the counterbalance weight P isarranged in the form of a piston and rod immersed in a cylinder containing water; the piston fittingthe cylinder so loosely that it could gradually assume the true position of equilibrium, while at thesame time its movement is so much resisted by the water, that it could not undergo sudden changesof position. This arrangement renders the dynamometer as steady in its action as could bedesired. The oldest draught-testing instruments are spring links on dial balances, analogous to theSalter balance. One of these instruments is illustrated, p. 1302 of this Dictionary. The divisions on the dial do not obey Hooks law of the distances travelled varying as thepulls, and it is necessary to determine all the divisions by actual experiment. Also the springsseem Hable to twist, probably dependent upon the exact points at the ends at which the pulls are

Text Appearing After Image:

applied; and this, combined with a little wear of the pins in the lever, seriously affects the uniformityot action of the index hand. The resistances of implements drawn by horses are very irregular and jerky, so that it isextremely difficult to read the mean draught on such an instrument with any degree of accura-y.ihese sprmg links have generally been superseded by integi-ating traction dynamometers. The plough dynamometer, the first of these instruments, illustrated in Figs. 1070 and 1071, con-sists of a light wrought-u-on frame, mounted on four wheels, three of these AAA belOg su))ported 506 DYNAMOMETER. on axles adjustable vertically and horizontally with clamps on the frame, exactly as in wheel-ploughs ; while the fourth wheel B, which is larger, is adjustable on the arc of a circle C, and drivesthe speed mechanism by a pitch chain and wheels D. The object of the vertical adjustments ofthe wheels is to permit one or two wheels to run in a furrow of any depth, while the others ru

Ergänzung zum Spons Dictionary of Engineering Civil Mechanical Military and Naval 1879 Buchillustrationen Pferd Maschinenbau Maschinenbau Technologie Geschichte der Technologie Bilder aus dem Internetarchiv

1879

Smithsonian Libraries

http://commons.wikimedia.org/

public domain