1849.] Eighteenth Memoir on the Law of Storms. 913 



1 . The sands forming a lee shore from the Western Brace to the 

 mouth of the Burampooter, with narrow channels and indifferent hold- 

 ing ground, and a sea in which no ship can hope to ride with safety in 

 a severe gale. 



2. The land to the Northward and Westward, and from Point 

 Palmiras to the Southward. 



3. The heavy set to the Westward over the sands, and for some 

 distance outside of the tails of the reefs. 



4. The Cyclone itself, with its uncertain track, and its attendant 

 storm-wave and storm-current, one or sometimes both, setting on to the 

 sands or to the coast about Point Palmiras. 



It is evident that in every Cyclone these four conditions must be all 

 taken into account ; and as there is now no sort of doubt about their 

 rotation, the usual tracks of the Cyclones become the next consider- 

 ation, for it is upon the track of the Cyclone and its rate of travelling 

 that the safe application of any rule must mainly depend. From all 

 our investigations up to the present day it appear, that at the Saudheads, 

 and from thence to 8° or 9° North, the tracks of the Cyclones may 

 lie from between E. by N. and S. by E., or S. S. E., to the W. by S. 

 or N. by W. or N. N. W., and as will be seen by the Chart of tracks 

 in the Horn Book that the average may be about from the S. E. or S. 

 E. by S., to the N. W. We can only lay down rules from the average, 

 noting where they would be affected by any great deviation towards the 

 extremes. 



The rate of travelling is the next consideration, and this too varies 

 very much, though it probably seldom exceeds ten miles per hour, 

 which we shall also assume as an average. 



Taking, first, the inward-bound ships, whether from Madras, from 

 Europe, or from the Eastward, we have to consider their position, and 

 then if the Cyclone is ahead, or astern, or abreast of them, and in 

 what part of the Bay its centre may be, for it is clear that all these 

 cases will vary as this element also may vary. 



The first case in which the Cyclone is ahead of the vessel, or in 

 other words the ship is behind the Cyclone, is simple enough : when 

 convinced of its being a Cyclone, the rule should indubitably be to 

 heave to, and this on two accounts ; the first to avoid running across, 

 or into the centre, or overtaking it, and the second because, even if a 



