USE OF METEOROLOGICAL OBSERVATIONS TO NAVIGATORS. ^5 



Thermometer. Hygs, 

 Cent. Fdhr. 



Between-decks , l6'5° Gl-?" 87** 



Gunroom 15-4 59*72 78 



Jan. the 30th, at noon, lat. 35° S., long. 7® E. [9°20'] ^ 



Poop 16-6 61-88 92 



Between-decks l6'7 62*06 91 



Gunroom 15*9 60-62 89 



The same day at midnight, lat. and long, the same. 



Poop 14-7 58-46 103 



Between-decks 17'3 63-14 98 



Gunroom 17*6 63-63 96 



General results. 



On comparing these different observations we find, with General con- 

 respect to the temperature, ^ usions. 



1, That the temperature of the air in the interior of the Temperature, 

 vessel is generally 3° or 4* [5*4* or 7*2° F.], higher than that 



of the exterior air. 



2, That the difference of temperature between the gun- 

 room and the between-decks was scarcely l°[l-8°F.], when, 

 by opening the parts and employing windsails,care was taken 

 to keep up a salutary current of air in the gunroom. 



3," That, circumstances being the same, the hold of the 

 ship is the hottest part. The exceptions to this rule appeared 

 to me to correspond with its being washed out, which was 

 done by introducing into it repeatedly large quantities of 

 water, the happy effects of which were both to clean and to 

 cool this place. 



With respect to moisture we find from the preceding ex- Moisture, 

 periments, 



4, That there is habitually more dampness in the vessel, 

 than in the open air. The few exceptions to this rule de- 

 pended on slight variations in the atmosphere, by which the 

 outer air was naturally affected sooner than that within the 

 ship. 



5, That the difference of moisture between the air within 

 and without the ship is generally greater than that of the 

 temperature, it frequently amounting to 10** or 12°. 



6, That, circumstances being the same, the gunroom is less 

 Vol. XXXUL-^Sept. 1812. F damp 



