S82 A NATURALIST IN THE PACIFIC 



NOTE 6 1 (page 215) 

 Meteorological Observations on the Summit of Mauna Loa 



The summit is formed of bare rock and sand, the phanerogamic 

 vegetation ceasing a couple of thousand feet below. Some low plant-forms 

 doubtless occur under the moist, warm conditions near the steam-cracks, 

 since Wilkes mentions his finding a small moss ; but with this exception 

 the surface may be described as sterile. 



Dryness of the Air and Electrical Phenomena. — Wilkes refers to the 

 association of these conditions more than once in his narrative. When- 

 ever, as sometimes happened, the dew point could not be obtained with 

 Pouillet's hygrometer, electricity was easily excited, and was developed in 

 large sparks. On taking off the clothes at night, sparks would appear. As 

 shown in the table subjoined, electrical phenomena were noticed during 

 the first few days of my sojourn on the summit when the relative humidity 

 was very low. My red blanket at night crackled in my hands and emitted 

 sparks, and a glowing line was produced by drawing the finger along. 

 Whilst the air was in this condition I observed that the wings of dead 

 butterflies lying on the ground stuck to my fingers tenaciously like a 

 needle to a magnet. The adhesiveness disappeared when the excessive 

 dryness gave place to humidity. The physiological effect on me of the 

 associated dryness and electrical state of the air was displayed in a hot, dry, 

 sweatless skin (cracking and chapping rapidly), severe headache and sore- 

 throat, general lassitude, and great irritability. When the weather changed 

 and the air became humid, these unpleasant symptoms quickly disappeared- 



As a result of these dry conditions on the summit of Mauna Loa, 

 decomposition does not occur. I found in one place on the top, on the 

 site of an old camp, the remains of a quarter of beef, the meat fresh but 

 dried up. From a water-bottle left behind by one of the party and 

 subsequently restored to him, I learned that the visit had been made in 

 the previous summer. This non-decomposition seems a little strange, 

 since, as remarked below, flies and other insects were not infrequent on the 

 summit. However, as Hann remarks, when speaking of mountain climates, 

 everything dries much more quickly at great altitudes ; animals that have 

 been shot, or killed by falling, become mummies without undergoing decay 

 (Schimper's Plant-Geography, 697). . . . The scorching power of the sun 

 in a sky usually cloudless, or nearly so, was a trying feature of my daily 

 experiences ; and I found that when I faced it with unshaded eyes during 

 my walks I suffered from severe pain in the eyeballs at night. 



Insects on the Summit. — It may seem a strange thing to relate, that in a 

 region apparently absolutely sterile, the flies and other winged insects 

 caused me much discomfort in my small tent when I was confined to it 

 through illness. When lying down one morning I noticed the house-fly, 

 the blue-bottle, and two or three other flies, small beetles not over a fifth o 



