Thomas Black was so anxious to take stellar observations, now that the sky was so clear, that he braved the rigour of the outside temperature, hoping to be able to examine some of the magnificent constellations twinkling on the zenith. But he was compelled to desist-his instruments "burnt" his hands! "Burnt" is the only word to express the sensation produced by touching a metallic body subjected to the influence of intense cold. Exactly similar results are produced by the sudden introduction of heat into an animate body, and the sudden withdrawal of the same from it, as the astronomer found to his cost when he left the skin of his fingers on his instruments. He had to give up taking observations.
However, the heavens made him the best amends in their power by displaying the most beautiful and indescribable phenomena of a lunar halo and an Aurora Borealis.
The lunar halo was a white corona with a pale red edge encircling the moon. This luminous meteor was about forty-five degrees in diameter, and was the result of the diffraction of the lunar rays through the small prismatic ice-crystals floating in the atmosphere. The queen of the night shone with renewed splendour and heightened beauty from the centre of the luminous ring, the colour and consistency of which resembled the milky transparent lunar rainbows which have been so often described by astronomers.
Fifteen hours later the heavens were lit up by a magnificent Aurora Borealis, the arch of which extended over more than a hundred geographical degrees. The vertex of this arch was situated in the magnetic meridian, and, as is often the case, the rays darted by the luminous meteor were of all the colours of the rainbow, red predominating. Here and there. the stars seemed to be floating in blood. Glowing lines of throbbing colour spread from the dark segment on the horizon, some of them passing the zenith and quenching the light of the moon in their electric waves, which oscillated and trembled as if swept by a current of air.
No description could give an adequate idea of the glory which flushed the northern sky, converting it into a vast dome of fire, but after the magnificent spectacle had been enjoyed for about half an hour, it suddenly disappeared-not fading gradually away after concentration of its rays, or a diminution of its splendour, but dying abruptly, as if an invisible hand had cut off the supply of electricity which gave it life.
It was time it was over, for the sake of Thomas Black, for in another five minutes he would have been frozen where he stood !
CHAPTER XIX.
A NEIGHBOURLY VISIT.
On the 2nd December; the intensity of the cold decreased. The phenomena of the lunar halo and Aurora Borealis were symptoms which a meteorologist would have been at no loss to interpret. They implied the existence of a certain quantity of watery vapour in the atmosphere, and the barometer fell slightly, whilst the thermometer rose to 15? above zero.