ATMOSPHERIC REFRACTION AT LOW TEMPERATURES. 687 



At the points of intersection of these halos, bright paraselenae, 

 forming five on the lower and two on the upper arcs, presented 

 themselves ; the moon and the intersections by the vertical ray- 

 exhibiting the most luminous. The moon was four days past the 

 full. 



On the same evening, between 9 p.m. and midnight, the magneto- 

 meter was deflected westwards 10° more than usual. The next 

 night the magnetometer was again unusually disturbed. There 

 was also a fainter display of paraselenjB. 



On December 1st a beautiful illustiation of the effect of intense 

 cold, fixing, as it were, the clouds and currents of air, and giving 

 them rounded outlines. Probably another remarkable effect due, 

 like the paraselenjc, to the floating of crystals or needles of ice in 

 the air. 



" The distant land on the southern shore, near Cape Lady 

 Franklin, was peculiarly refracted, and appeared to be consider- 

 ably nearer than our positive knowledge would warrant, displaying 

 very beautifully its particular features." A delicate salmon tint 

 pervaded the horizon. 



6. Halos, &c. — McClintock, p. 74. 



Dec. 4, Dawn at llli. Om. a.m. A well-marked halo and several 

 paraselenas between 7h. and lOh. p.m., consisting of five false 

 moons, three arcs of halos, and a horizontal belt of light, round the 

 heavens and passing through the moon. 



7. Twilight throughout the Winter. 



With regard to the existence of twilight through the winter, 

 McClintock says : — " On the mid-winter day (December 21st) at 

 " noon we could just read type similar to the leading article of the 

 " ' Times.' Few people could read more than two or three lines 

 " without their eyes aching." 



Parry in his first voyage to Melville Island says : — " Up to the 

 " shortest day of the year the I'eturn of each successive day was 

 " very decidedly marked by a considerable twilight for some time 

 " about noon, that on the shortest day being sufficient to enable 

 " us to walk out very comfortably for nearly two hours. There 

 " was usually a beautiful arch of bright red light in the southern 

 " horizon for an hour or two." 



8. Parky's Second Voyage to discover a North-west 

 Passage. 



Analysis of Air, p. 240. 



Bottles of air collected at Igloolik and packed in oakum were 

 examined by Prof. Faraday, whose results showed that the air 

 contained 20-5885 per cent, of oxygen, whilst the air of the 

 Laboratory at the Royal Institution contained 21-9625 per cent. 



