It is these violent changes in velocity and direction, and the soft and treacherous character of the soil, that make the question of foundations in water a peculiarly difficult one in India. The sudden shifting of a shoal may dam up the archway of a bridge, and the increased velocity in the narrowed waterway acting on such soil, often scours out a hole 30 feet deep in a single night. Almost every rainy season in India sees failures and disasters on this score, and the most carefully considered design may be a mass of ruins in twenty-four hours. The Bengal mode of dealing with these difficulties is to carry down every pier-cylinder, whether of masonry or iron, to such a depth as either to rest in the firm soil below, or to be absolutely beyond the reach of any possible scour, but to put no flooring or curtain walls by which the stream can possibly be checked and incited to tear up the bed. The Madras system is to be content with a much smaller depth of foundation, but to provide, by means of a flooring and apron walls, a compact dam of masonry solidly bound together, front and rear and from shore to shore, which shall be proof against any action of the stream. The subject is one which has excited much discussion, but is too long to enter upon here. You will find it treated of in the works already quoted.
I have now described the most important specialities of Indian foundations, and have to ask you to follow me in the first section of what I may call special engineering constructions, _viz. Buildings_, or rather dwellings, such as houses, barracks, churches, and the like. The subject is, of course, a very extensive one, and I only propose here to draw attention to those buildings which the Indian engineer is generally called upon to construct. First, then, let us take Indian Barracks, that is, barracks for English soldiers in India, as they are not only the most important buildings that you will have to deal with, but there are many vexed questions concerning them which are still far from settled, and which apply equally to all dwellings erected for Europeans in an Indian climate.
In the earlier days of our Indian empire, the barracks constructed for the European soldiers were often built on ill-chosen sites; the rooms were low and a great deal too crowded, and drainage and conservancy scarcely thought of; the consequence was a frightful mortality, which often reached the high figure of 70 to 90 per thousand. As the important subject of sanitation received more and more attention in England, it was not likely it should be neglected in India, where a tropical climate aggravated the results of neglect of sanitary laws, and where every English soldier who died cost the Government a large sum of money to replace him.