MAUNA LOA. 



145 



Christmas-day set in quite stormy, with snow and a gale from the 

 southwest ; it was very cold, and the only way we had of keeping 

 warm was to wrap ourselves up with blankets and furs. We had just 

 wood enough to heat a little chocolate. 



The small instruments having arrived, I began some of the obser- 

 vations. 



While the rest were employed in making our tents as tight, as pos- 

 sible, in the one Dr. Judd and myself occupied, we discovered a great 

 deposit of moisture, which, on examination, was found to be caused by 

 steam issuing through a crack in the lava. On placing a thermometer 

 in it, it rose to 68°. The tent was forty feet from the edge of the pre- 

 cipice of the crater, and it was not surprising that the steam should find 

 its way up from the fires beneath. As it somewhat annoyed us, we 

 pounded and filled the seam full of broken pieces of lava. This circum- 

 stance led to the discovery of a small piece of moss, the only living 

 thing, either animal or vegetable, that was found within six miles dis- 

 tance, or within four thousand feet of the height of the terminal crater. 

 This moss was here nourished by the steam that escaped, which sup- 

 plied it with warmth and moisture. 



This day we made many experiments on the temperature of boiling 

 water : the mean of the observations gave the boiling temperature at 

 188°, being five hundred and sixty feet to each degree of temperature. 

 At the volcano of Kilauea, I had found it less than five hundred and 

 fifty feet to each degree; while the result of careful experiments at the 

 Sunday Station, gave five hundred and fifty-five feet to the degree, and 

 at the Recruiting Station, five hun- 

 dred and fifty-eight feet. 



We also employed ourselves in 

 building a high stone wall around 

 a space large enough to contain the 

 houses and tents, when they should 

 all arrive, having found the necessity 

 of it to protect ourselves from the 

 violent winds. Besides this, each 

 tent was to be surrounded by a se- 

 parate wall, up as high as the eaves, 

 when completed. The plan was 

 as exhibited in the annexed wood- 

 cut. 



1. Pendulum-house. 2. Captain Wilkes's tent. 3. Officers' tent. 4, 5 and 6. Men's 



quarters. 7. Magnetic house. 8. Observatory. 9. Store-house. 10. Wood-house. 11. 



Kitchen. 12. Thermometer and barometer house. 13. Entrance. 

 VOL. IV. N 10 



