162 M A U N A L O A. 



rienced at Honolulu, on the nights of the 23d and 24th, a very heavy- 

 storm from the southwest, simultaneously with the one that annoyed 

 us on the mountain. A greater degree of cold was experienced there 

 than they had had for years. At Hilo, during this time, very light 

 variable winds and calms prevailed. 



We were employed this day in erecting the pendulum-house, over 

 which was placed a thick hair-cloth covering, and outside of all, a 

 No. 2 canvass tent, surrounding the whole house, and enclosing a 

 stratum of air. On the outer side a wall was built up to the eaves of 

 the house, and all the cords drawn tightly through it. 



It was with some difficulty that any level spot was found sufiB- 

 ciently large to place even the pendulum-frame, and we were obliged 

 to cut away with our axes and chisels, a portion of the lava that was 

 uneven, until a suitable place was made. 



The temperature at night was 17°; the weather clear and cold. 



On the 1st of January, 1841, we were still erecting the pendulum- 

 houses, and building stone walls. Dr. Judd, the sergeant, and Brooks, 

 descended into the crater : they made the descent on the east bank, 

 among large blocks of lava, and reached the bottom in about an hour. 

 There they were surrounded by huge clinkers, and ridges running 

 generally north and south in lines across the crater ; between these 

 was the pahoihoi, or smooth lava. They passed over these obstruc- 

 tions to the southwest, and found in places many salts, among which 

 were sulphate of soda, and sulphate of lime. Four-fifths of the way 

 across was a hill, two hundred feet high, composed of scoria and 

 pumice, with fissures emitting sulphurous acid gas. To the west was 

 a plain full of cracks and fissures, all emitting more or less steam 

 and gas. 



They found the west wall perpendicular : its lower strata were 

 composed of a gray basalt. For three-fourths of the distance up, it 

 had a dingy yellow colour. Above this, there are a number of thin 

 layers, apparently dipping to the southwest, with the slope of the 

 mountain. 



They also visited many steam-cracks on the northeast side, from 

 which fumes of sulphurous acid gas were emitted ; no hydrogen was 

 found in the gas, which extinguished flame without producing 

 explosion. 



Specimens of sulphate of lime, carbonate of magnesia, sulphate of 

 ammonia, and carbonate of lime, were found in beautiful crystals by 



