ON THE FLOES 293 
Went out to the outer berg, where there was quite a 
collection of people, mostly in connection with Ponting, 
who had brought camera and flashlight. 
It was beautifully calm and comparatively warm. It 
was good to hear the gay chatter and laughter, and sec 
ponies and their leaders come up out of the gloom to add 
liveliness to the scene. The sky was extraordinarily clear 
at noon and to the north very bright. 
We have had an exceptionally large tidal range during 
the last three days — it has upset the tide gauge arrange- 
ments and brought a little doubt on the method. Day is 
going into the question, which we thoroughly discussed 
to-day. Tidal measurements will be worse than useless 
unless we can be sure of the accuracy of our methods. 
Pools of salt water have formed over the beach floes in 
consequence of the high tide, and in the chase of the crab- 
cater to-day very brilliant flashes of phosphorescent light 
appeared in these pools. We think it due to a small 
copepod. I have just found a reference to the same 
phenomenon in Nordcnskiold's * Vega.' He, and apparently 
Bcllot before him, noted the phenomenon. An interesting 
instance of bi-polarity. 
Another interesting phenomenon observed to-day was 
a cirrus cloud lit by sunlight. It was seen by Wilson and 
Bowers 5 0 above the northern horizon — the sun is 9 0 
below our horizon, and without refraction we calculate a 
cloud could be seen which was 12 miles high. Allowing 
refraction the phenomenon appears very possible. 
Wednesday , May 31. — The sky was overcast this 
morning and the temperature up to - 1 3 0 . Went out 
