### Contents

 00 15 To delineate a squarethreaded screw 18 12 31 To find the solidity or capacity of 42 Table of polygons 46 To find the convex surface and solidity 48
 14 53 39 55 Proportional breadths for sixsided nuts 109 50 118 On the smelting of metallic ores 229 Definitions 268

### Popular passages

Page 188 - MECHANICAL POWERS are certain simple instruments employed in raising greater weights, or overcoming greater resistance than could be effected by the direct application of natural strength. They are usually accounted six in number; viz. the Lever, the Wheel and Axle, the Pulley, the Inclined Plane, the Wedge, and the Screw.
Page 18 - From half the sum of the three sides, subtract each side severally; multiply the half sum, and the three remainders together, and the square root of the product will be the area required. Example. — Required the area of a triangle, whose sides are 50, 40, and 30 feet. 50 + 40+30 ; — 60, half the sum of the three sides.
Page 29 - To twice the length of the base add the length of the edge ; multiply the sum by the breadth of the base, and by one-sixth of the height.
Page 126 - To find the absolute strength of a rectangular beam, when fixed at one end and loaded at the other. RULE. Multiply the value of S by the depth of the beam, and by the area of its section, both in inches: divide the product by the leverage in inches, and the quotient equal the absolute strength of the beam in Ibs.
Page 129 - ... by compression is different according to the proportion between its length and area of its cross section ; and supposing the form that of a cylinder whose length is less- than seven or eight times its diameter, it is impossible to bend it by any force applied longitudinally, as it will be destroyed by splitting before that bending can take place; but when the length exceeds this, the column will bend under a certain load, and be ultimately destroyed by a similar kind of action to that which has...
Page 270 - To find the mimber indicated by a given logarithm. Look for the decimal part of the given logarithm in the different columns, and if it cannot be found exactly, take the next less. Then under N in the left-hand column, and in a line with the logarithm found, are three figures of the number required, and on the top of the column in which the found logarithm stands is one figure more ; i place the decimal point as indicated by the logarithmic index, ! which determines the sum, properly valued, as required.
Page 16 - CUBIC MEASURE 1728 cubic inches = 1 cubic foot 27 cubic feet = 1 cubic yard...
Page 246 - ... reckoning from that point of the stroke where the steam of uniform elastic force is cut off : but it is more properly the force which steam is capable of exerting, when expanded to a known number of times its original bulk. And condensation, here understood, is the abstraction or reduction of heat by another body, and consequently not properly a contained property of the steam, but an effect produced by combined agency, in which steam is the principal ; because any colder body will extract the...
Page 269 - The whole numbers of the series of logarithms, as 1, y, 3, &c., are called the indices, or characteristics of the logarithm, and which must be added to the logarithm obtained by the Table, in proportion to the number of figures contained in the given sum. Thus, suppose the logarithm be required for a sum of only two figures, the index is 1 ; if of three figures, the index is 2^ and if of four figures, the index is 3, &c.
Page 245 - In the heating of buildings, its economy, efficiency, and simplicity of application are alike acknowledged; the steam being simply conducted through all the departments by pipes, by extent of circulation condenses — the latent heat being thus given to the pipes, and diffused by radiation. In boiling, its efficiency is considerably increased, if advantage be taken of sufficiently inclosing the fluid, and reducing the pressure on its surface, by means of an air-pump.