348 



Meteurolo(jica( and hudro(jra}>hical 



stopper was inserted, and the superfluous fluid wiped away, 

 The greatest difference between the temperatures of the con- 

 tained and surrounding fluids, did not, in any of the experi- 

 ments, exceed 0°-2 Fahr. 



Table I. Thermometrical Observations, ^-f., on a Voyage 

 from Gibraltar to Barbadoes, in March 1841. 



On the 10th March, a very heavy squall occurred, which, 

 fortunately, only split a topsail and topgallant-sail. At 9 A.M. 

 there was a very slight breeze from the SE.,* which died 

 away tOAvards noon ; at this time it was densely overcast, and 

 the clouds high. All round the southern horizon a sort of mi- 

 rage appeared partially, running rapidly from one place to ano- 

 ther and abruptly b-eaking its continuity thus, "^■--~- 



The master of the ship informed me he had frequently seen a 

 similar appearance off the Cape ; but he did not seem aware 

 of its nature. The same appearances continued until 1 P.M., 

 when, the deck having been left in charge of a very inexpe- 

 rienced young man, the squall suddenly came on, from about 

 SSE., with great violence, preceded only by a few small drops 



* All the bearings are corrected for the variation of the compass. 



