Spons' dictionary of engineering, ed. by O. Byrne (and Spon). 8 div, Volume 87

Front Cover
 

Common terms and phrases

Popular passages

Page 2771 - The better to secure this uniform distribution of the pressure, the sills of one row are so laid as to break joints with the other; and to prevent the ends of the sills from yielding the usual precaution is taken to place short sills at the joints, either beneath the main sills, or on the same level with them. The boards are laid perpendicular to the axis of the road, experience having shown that this position is as favorable to their wear and tear as any other, and is otherwise the most economical.
Page 3056 - ... of water to escape by artificial issues. We are also liable to be baffled by the great thickness either of porous or impervious strata, or by the dip of the beds, which may carry off the waters from adjoining high lands to some trough in an opposite direction, as when the borings are made at the foot of an escarpment where the strata incline inwards, or in a direction opposite to the face of the cliffs.
Page 2771 - ... inches beyond those next to them, for the purpose of presenting a short shoulder to the wheels of vehicles, to facilitate their coming upon the plank surface, when from any cause they may have turned aside. On some roads the boards have been spiked to the sills ; but this is...
Page 2979 - ... will fix it in position by means of very fine points on the under side. It is now ready to lay off the given angle, or any number of angles that may be required, which is done by turning the pinion d till the opposite vernier reads the required angle. Then press...
Page 2763 - Cours de construction des ouvrages, qui établissent la Navigation des Rivières et des canaux, professé à l'École des Ponts et chaussées de 1832 à 1841.
Page 2780 - ... be taken, it may be asserted that the same quantity of material would be necessary for the repair of a road, whether wide or narrow, which was subjected to the same amount of traffic. On the narrow road, the traffic, being confined more to one track, would wear the road more severely than when spread over a larger surface. The expense of spreading the material over the wider road would be somewhat greater, but the cost of the materials might be taken as the same.
Page 2974 - Repeat this operation, till the bubble remains accurately in the centre of its run in both positions of the telescope ; and then turning the vernier plate round till the telescope is over the other pair of parallel plate screws, bring the bubble again to the centre of its run by turning these screws. The bubble will now retain its position, while the vernier plate is turned completely round, showing that the internal azimuthal axis, about...
Page 3056 - ... again replenished after a continuance of rain. Many of them are probably indebted for the constancy and uniformity of their volume to the great extent of the subterranean reservoirs with which they communicate, and the time required for these to empty themselves by percolation. Such a gradual and regulated discharge is exhibited, though in a less perfect degree, in...
Page 2775 - At a walking pace, the resistance to traction is the same, under the same circumstances, for carriages with springs and for carriages without springs.
Page 2695 - The immediate object of the reconnoissance is to select one or more trial lines, from which the final route may be ultimately determined. When there are no maps of the section traversed, or when those which can be procured are indefinite or inaccurate, the work of reconnoitering will be much increased.

Bibliographic information