Page:Blackwood's Magazine volume 002.djvu/724

prefers spiders to any vegetable food. When any person speaks, it fixes its eyes upon his mouth, and if it can possibly get upon his shoulder, it touches his teeth or tongue with its fingers. To travellers who collect insects, it is particularly dangerous. Let them take what care they will of their collections, the Titi soon discovers them; he takes the specimens, without pricking his fingers, of the pins by which they are fastened, and greedily devours them. Such is the discrimination of these little apes, that one of them could distinguish those plates in Cuvier's Natural History, which represented insects. At the sight of them, though uncoloured, the Titi would immediately stretch out his little hand in the hope of catching a grasshopper, a wasp, or a dragon fly; but remained quite indifferent when he was shewn engravings of mammalia, birds, and other animals.

Mr H. C. Jennings announces, that he has discovered a Method of insulating the Magnetic Needle, in such a degree as, under the ordinary circumstances, will protect the compass from false and dangerous attractions, by the designed or accidental approach of iron, or substances containing it; a defect which has already cost the government and nation many lives and ships.—A striking instance of the uncertainty and imperfection of the ordinary compass was exhibited in the loss of H.M.S. Apollo, and 70 sail of convoy; and if this event were the only one of the kind on record, it would be sufficient to convince every person of the vast importance of a method which shall effectually preclude the possibility of the recurrence of such a disaster.

A similar invention has been made in Scotland, by a shoemaker at Linlithgow, who has employed it very ingeniously, in masking the action of the magnets that give motion to a lever, which he supposes will be a perpetual motion.

Notice respecting the Expedition to the North Pole.—As the public curiosity has been much excited by the Scientific Expedition to the Arctic Regions, which is to sail on the 24th of March, we have been anxious to lay before our readers all the information which can be readily procured relative to this interesting subject.

The Isabella, the Alexander, the Dorothea, and the Trent, are the vessels which are to be employed on this expedition. The Isabella and the Alexander proceed with a north-westerly course to Davis's Straits, for the purpose of discovering a passage into the Pacific Ocean. The Dorothea and the Trent proceed to the eastward of Greenland, and advance in a northerly direction, with the hope of reaching the Pole, and arriving at that route at Behring's Straits. An ice boat of a new construction has been laid down for the Isabella. It is 28 feet long, 7 feet broad, and 4 feet high, rigged with sprit-sails, and made to pull fourteen oars, double banked. It is also made with three keels, for the purpose of being drawn over the ice. This boat is fitted with copper tanks for spirits and water, and with a stove in the sternsheets, the funnel leading forward along the thwarts to key the men warm. It is also to have awnings, and a kind of battens athwart the bottom, for the men to lie on. This boat has been planned by Lieutenant Cawly of the navy.

The celebrated artist Troughton is busily employed in constructing dipping needles and dip sectors, for making magnetical observations; and he has revived the idea of producing an artificial horizon, by giving a rapid motion of rotation to a reflecting plane, which preserves its horizontality, whatever be the motion of the body upon which it revolves. This contrivance, which we believe was first suggested by Serson, and afterwards improved by Mr Weir, has been long abandoned as hopeless; but we have little doubt that the genius of Troughton will surmount the difficulties which preceding artists had found it impossible to overcome.

One of the officers of the Isabella has undertaken to make a series of regular observations with the new barometer, or sympiesometer, invented by Mr Adie of this city; and several of the officers have been furnished with queries, drawn up by different scientific individuals, with the view of directing their attention to the various phenomena which are likely to present themselves in the Polar Regions.

German Universities.—The following account is given of the present state of the German universities:—

Thus, instead of the 36 universities which existed previously to 1802, there are now but 19, of which 5 are Catholic, 2 mixed, and the rest Protestant. The total number of students is about 8,500, which, taking the population of all Germany at 29¹⁄₂ millions, is about 288 for every million.

Instrument for distinguishing the Precious Stones.—Dr Brewster has lately constructed an instrument for distinguishing the precious stones from each other, and from artificial imitations of them, even when they