Misceilaneous. 177 
in twelve fathoms of water. Luminosity was great, but not so 
intense as when a grey cloudiness, due to myriads of tiny creatures, 
tinges the fjord waters. This cloudiness is probably due to migra- 
tion, and always precedes the arrival of herring-shoals; ib is most 
marked in spring and autumn, and usually occurs with a westerly 
wind. 
*¢ All through November the luminosity was great, but especially 
so on the 23rd, when we had hail and lightning during the day and 
the aurora at night. The average temperature of surface-water 
during this month was 42° F. 
“On December 16 a violent east gale was blowing. Temperature 
of air about freezing-point, and surface-water 38° to 40° F. The 
whole fjord was streaked with fire; and the shore-line seemed a 
- seething mass of flame. Some forms emitted disks of light which 
appeared to be 3 inches across. 
“ December 23, 1881. Thermometer 26° F. in air, and 37° F. in 
water. Splendid display of aurora, and sea gloriously luminous.” 
On December 27 I left Stavanger for Bergen; and at 5 a.m. the 
luminosity of the sea was wonderful, pillars of flame, disks and stars 
of fire tumbling one over another in the wake of the vessel; some 
emitted a yellow and others a white phosphorescent lingering light ; 
but many gave forth steel-blue flashes exactly like electric sparks. 
After spending a week examining the fine natural-history mu- 
seum in Bergen, I returned to Stavanger on January 3rd, 1882, and 
the sea was luminous as usual. Constant luminosity during January 
and February. 
In March I went to Haugesund to see the herring-fishery, and I 
found the waters grey with life and very luminous. I then went 
on into the Hardangerfjord; and as we crashed through the ice at 
Norheimsund, I noticed that it seemed to emit light on fracture. 
{had read somewhere that this was supposed to be due to electricity ; 
so I got up some buckets of ice and water: eliminating the ice, I 
found the remaining water perfectly luminous, and I noticed that 
the steel-blue flash seemed to predominate. Here, then, was the 
explanation ; but as I had not a microscope of sufficient power with 
me, I could not carry out my researches. As these creatures live 
quite well in water at freezing-point, possibly they may be even 
included in ice, and make long journeys without injury. 
At Odde I noticed the same phenomenon, the ice being 3 inches 
thick. 
I left Stavanger for Hull in April, and it was worthy of remark 
that the waters along the Norwegian coast were luminous; yet as 
we steamed westward the luminosity gradually diminished ; hence 
I think that certain currents carry these animals northward along 
the coast and into the fjords. 
In conclusion, I may sum up as follows :— 
(a) That the luminosity of sea-water occurs all the year round; 
even when ice is present. 
(() That it is greater during electrical atmospheric disturbances, 
and is partly caused by electricity. 
(y) That it is also well marked during the migrations of fishes, 
Ann. & Mag. N. Hist. Ser. 5. Vol. x. 12 
