A great impetus was given to the study of terrestrial magnetism by the publication of M. Hansteen’s labors; and the various arctic expeditions sent out by the country did much toward making us acquainted with the laws of magnetism in the northern regions. One of these expeditions led to the discovery of the north magnetic pole, or that point where the dipping-needle assumes a vertical position. The discovery was made by Captain Sir James Ross, who sailed with his uncle Sir John Ross, in a voyage undertaken in search of a northwest passage. He left his uncle’s ship with a party for the sole purpose of reaching this interesting magnetical point, which a series of observations assured him could not be very far distant. The following extract from his journal communicating his discovery will be read with interest. Under the date of the 31st of May 1831, he writes: “We were now within fourteen miles of the calculated position of the magnetic pole, and my anxiety, therefore, did not permit me to do or endure any thing which might delay my arrival at the long wished-for spot. I resolved, therefore, to leave behind the greater part of our baggage and provisions, and to take onward nothing more than was strictly necessary, lest bad weather or other accidents should be added to delay, or lest unforeseen circumstances, still more untoward, should deprive me entirely of the high gratification which I could not but look to in accomplishing this most-desired object. We commenced, therefore, a most rapid march, comparatively disencumbered as we now were; and persevering with all our might, we reached the calculated place at eight in the morning of the 1st of June. The amount of the dip, as indicated by my dipping-needle, was 89° 59’, being thus within one minute of the vertical; while the proximity at least of this magnetic pole, if not its actual existence where we stood, was further confirmed by the total inaction of the several horizontal needles then in my possession. These were suspended in the most delicate manner possible, but there was not one which showed the slightest effort to move from the position in which it was placed—a fact which even the most moderately-informed of readers must know to be one which proves that the centre of attraction lies at a very small horizontal distance, if at any. The land at this place is very low near the coast, but it rises into ridges of fifty or sixty feet high about a mile inland. We could have wished that a place so important had possessed more of mark or note. But nature had here erected no monument to denote the spot that she had chosen as the centre of one of her great and dark powers. We had abundance of materials for building in the fragments of limestone that covered the beach, and we therefore erected a cairn of some magnitude, under which we buried a canister containing a record of the interesting fact, only regretting that we had not the means of