April — june 1857.] Breakwater for Madras. 151 



seas in this locality are far below those in that of the Plymouth 

 breakwater for instance, which is exposed to the long continued 

 gales that sweep across the wide stretch of the Atlantic. Our 

 gales never continue many days, and in the hurricanes the wind 

 never continues many hours in one direction. The comparatively 

 small power of the seas is shown by the fact that after a hurricane, 

 when the sea has risen above its ordinary level, very few stones 

 are thrown up on the beach out of the bulwark. 



" All experience tends to show that gales of wind and hurri- 

 canes have occured at intervals of several years and that there are 

 timely warnings indicative of their approach and also that they are 

 of short duration. For instance in the heavy gale of October 1842, 

 the sea and surf raged with great violence from 8 a. m., on 

 the 23rd to 2 A. m., on the 24th, yet at 6 a. m., within 24 hours 

 from the commencement of the gale, and a few hours after its de- 

 cline, the surf had so completely subsided, that boats and catama- 

 rans were enabled to ply." — Captain Biden. 



Supposing that the work is placed in 6 J fathoms at low water, 

 that the long slope extends from one yard below low water to 2 

 yards above high water, and that the top of the work is 4 yards 

 above high water, the section would contain about 800 square 

 yards, or 1000 tons per yard in length. 



Such a work may be made of any length at first and extended 

 as the trade of the port increase to any amount. 



During the stormy season the number of vessels in the port will 

 always be moderate, because the coasting trade is stopped, and du- 

 ring the fine season if all the vessels occasionally cannot be covered 

 by it, they would still all have the benefit of the cheap, safe and 

 convenient, communication with the shore that it would afford, so 

 that as soon as a moderate length is executed all the main points 

 will be gained. It must also be remembered that very soon when 

 the coast canal is extended to the Godavery in the North, and the 

 Cauvary in the South, the coasting trade will be greatly diminished, 

 for the canal transit will be greatly cheaper than that by the coast. 

 On these accounts 1000 yards length of breakwater will afford the 



