Course of Civil Engineering: Comprising Plane Trigonometry, Surveying, and Levelling. With Their Application to the Construction of Common Roads, Railways, Canals ...S.J. Machen, 1843 |
Common terms and phrases
altitude angle of friction answer ascertain boat bottom breadth broken stones calculated canal carriage centre centrifugal force chain column considerable construction convey curvature curve datum line deep depth diameter difference of level direction distance drainage Dublin earth edge-rail effect embankment employed engineer equal excavations expense fall feet force friction gates grass gravel ground height horizontal horse improvement inches inclined plane injurious instrument Ireland labour laid lake land length levelling instrument load locks Lough Beg Lough Neagh lower main drain manure means ment miles moss multiplied necessary observed pass plough Portglenone practice pressure prevent produce quantity of water rail rail-roads railway refraction render reservoirs right angles river river Dodder road shews side sixth column slope sods soil speed staff station stratum stream subsoil sufficient supply surface telescope temperature theodolite tion town track upper velocity vertical wheels yards
Popular passages
Page 186 - ... the height of every embankment, and the depth of every cutting, and a datum horizontal line which shall be the same throughout the whole length of the work, or any branch thereof respectively, and shall be referred to some fixed point stated in writing on the section, near some portion of such work, and, in the case of a canal, cut, navigation, public carriage road, or railway, near either of the termini.
Page 73 - All the irregularities of the upper part of the said pavement are to be broken off by the hammer, and all the interstices to be filled with stone chips firmly wedged or packed by hand with a light hammer, so that when the whole pavement is finished there shall be a convexity of four inches in the breadth of fifteen feet from the centre.
Page 174 - ... boat is 4320 cubic feet, and in ascertaining what water may be necessary for supplying the canal, allowing for waste by evaporation and soakage, it is found (according to the number of boats that may be expected to pass), that there will not be above 800 cubic feet for each ; and hence, it is added, it will be necessary to save five-sixths of the whole ; to do which ten cisterns are directed to be made, each of which must be one foot deep, and each have a surface of 360 feet superficial. The...
Page 73 - The middle 18 feet of pavement is to be coated with hard stones to the depth of 6 inches. Four of these 6 iuches to be first put on and worked in by carriages and horses, care being taken to rake in the ruts until the surface becomes firm and consolidated, after which the remaining 2 inches are to be put on.
Page 149 - ... down again, a portion of a continuous flexible valve or flap, of peculiar construction, covering the aperture ; and it is the very simple, ingenious, and efficient mode of successively opening, and closing down and hermetically sealing this valve, as each train advances and moves on, that constitutes the merit of the invention, and the foundation of the patent ; the operation consisting first, in opening the valve to admit the free admission of the external air, to press on the back of the piston,...
Page 73 - Four of these six inches to be first put on, and worked in by carriages and horses ; care being taken to rake in the ruts until the surface becomes firm and consolidated, after which the remaining two inches are to be put on.
Page 241 - Europe occupy the place of immense forests of pine and oak, which have many of them disappeared within the historical era. Such changes are brought about by the fall of trees and the stagnation of water, caused by their trunks and branches obstructing the free drainage of the atmospheric waters, and giving rise to a marsh.
Page 2 - Also one place is higher than another, or out of level with it, when it is farther from the centre of the earth : and a line equally distant from that centre, in all its points, is called the line of true level. Hence, because the earth is round, that line must be a curve, and make a part of the earth's circumference, or at least be parallel to it, and concentrical with it ; as the line BCFG, which has all its points equally distant from A,.
Page 238 - A velocity of six inches will lift fine sand, eight inches will lift sand as coarse as linseed, twelve inches will sweep along fine gravel, twentyfour inches will roll along rounded pebbles an inch diameter, and it requires three feet per second at the bottom to sweep along shivery angular stones of the size of an egg.
Page 73 - Upon the level bed prepared for the road materials, a bottom course, or layer of stones, is to be set by hand, in form of a close firm pavement ; the stones set in the middle of the road are to be 7 inches in depth ; at 9 feet from the centre, 5 inches ; at 12 feet from the centre, 4 inches ; and at 15 feet, 3 inches.