36 



REPORT — 1851. 



Register of Meteorological Phcenomena at Huggate in Yorkshire. 

 By the Rev. T. Rankin. 



Law of Storms On Mooring Ships in Revolving Gales. 



By Lieut.-Colonel Wm. Reid, Royal Engineers, F.R.S. 



In this paper 1 propose to explain a subject which I had overlooked, until Hiy at- 

 tention was lately drawn to it by Sir James Dombrain, who commands the Revenue 

 vessels on the coast of Ireland. He informed me, that after studying the first work 

 I had published on the Law of Storms, he observed that when he let go his right 

 hand, or starboard bower anchor, the first, and afterwards the left-hand, or port 

 bower anchor, in gales on the coast of Ireland, veering from south-east by south to 

 west, that the cables twisted or fouled as the vessels swung round to the veering 

 wind ; and that this observation led him to change all his best bower anchors from 

 the starboard to the port side of his vessels. 



This would generally be the rule on the coast of Ireland. But these remarks led 

 me to consider what the rule should be on either side of the centre of a progressive 

 revolving gale, and whether it would not be different in the southern hemisphere, in 

 which gales revolve in the opposite way to what they do in the northern hemisphere. 

 I may here explain, that when two cables are laid out with anchors from the head 

 of a ship, it becomes very difficult to weigh anchor with only one crossing in 

 the cables, and impossible to do so with a double cross, called an elbow ; and hence 

 the importance of riding at anchor without crossing or fouling the cables when ships 

 are moored. 



Fig. 1. 



Figure for 

 the North- 

 ern hemi- 

 sphere. 



"A* 



Ship in 



right-hand 

 side of gale. 



The first diagram is intended to represent a whirlwind gale 800 or 1000 miles in 

 diameter, moving on a north-east course, and supposed to be approaching the British 

 Islands, but with its centre on the Atlantic ; and such gales are the most frequent 

 on the British coasts. In such a gale as is here represented, the wind on the British 

 coasts would set in between east and south, and veer by the south to the west. If 

 a ship were to come to anchor with a single anchor, as that marked (), with the 



