280 British Association for the Advancement of Science. 



ing, may be ascertained ; if the 

 ship be then so manoeuvred as 

 that the wind shall veer aft in- 

 stead of ahead,]and the vessel is 

 made to come up, instead of be- 

 ing allowed to break off, she will 

 run out of the storm altogether ; 

 but, if the contrary course be 

 taken, either through chance or 

 ignorance, she goes right into 

 the whirl, and runs a great risk of being suddenly taken aback, 

 but most assuredly will meet the opposite wind in passing out 

 through the whirl. To accomplish her object, he showed, by 

 a diagram,* (as is above represented.) that it was necessary 

 the ship should be laid on opposite tacks, on opposite sides of 

 a storm, as may be understood by drawing a number of con- 

 centric circles to represent the whirl of the hurricane, and then 

 different lines across these, to represent the course of ships enter- 

 ing into, or going through the storm ; but to attempt the full ex- 

 planation of even this, would extend much beyond our limits. 



The apparent accordance of the force of storms with the law 

 of magnetic intensity, as exhibited by Major Sabine's report, is 

 remarkable. It had been frequently remarked that no storms 

 occur at St. Helena. He had therefore felt much curiosity to 

 know the degree of magnetic intensity there, and was not a little 

 struck at finding it the lowest yet ascertained on the globe. 

 Major Sabine's Isodynamic lines, to express less than unity, are 

 only marked there, and they appear as it were to mark the true 

 Pacific Ocean of the world. The lines of greatest intensity, on 

 the contrary, seem to correspond with the localities of typhoons 

 and hurricanes ; for we find the meridian of the American mag- 

 netic pole passing not far from the Caribbean sea, and that of the 

 Siberian pole through the China sea. 



Prof. A. D. Bache, of Philadelphia, stated that he rose to thank 

 Col. Reid, for the very handsome manner in which he had 

 brought forward the theory of his countryman, Mr. Redfield. 



* A diagram similar to this, but in some respects more full and explicit, together 

 with a discussion of the methods of escaping a storm, was given by Mr. Redfield in 

 Vol. XXXI, p. 117, of this Journal. — Eds. 



