Trigonometrical surveying, levelling, and railway engineering

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1842 Excerpt: ...views on most points than in Dr Lardner's; yet, in the present case, from the remarks I have made above, and what has occurred to my own knowledge, it would appear that there is some foundation for Dr Lardner's results. On the preceding pi.inciples will be compared the relative merits of two assumed lines of railway, in which the values of the respective gradients ai#e given in a column adjacent to the corresponding measured distances of the slopes, &c., for a passenger train of 50 tons only, by way of example. On comparing the results of these two lines, designated by A and B, it appears that A loses only about one-seventh of a mile, while B loses about a mile and a half in steam-power or in time by means of the gradients alone, when the effects of the slopes are estimated by Mr Barlow's tables; but this does not give a proper estimate of the relative expenses of the lines. This is obtained from a comparison of the mean horizontal distances in the right-hand columns. Thus A has 33.882 miles of mean horizontal distance, while B has only 30.337 miles. The difference of these is 3.545 miles, the loss of A above B, in passing once along the line, and of course double of this, or about 7 miles, in one trip forward and back, of steam-power or of time. These conclusions are independent of 5 miles of actual measured distance, for the construction of which additional miles funds must be provided, which causes an immense loss, or useless expenditure of money to the shareholders of A's line, while that of B is more effective. Besides entailing the expenses of construction on the shareholders for.these additional useless 5 miles, the expenses of transit over them must be charged on goods and passengers, thus compelling those who use the railway to suffer a severe ...