A similar discovery, which was made about the same time in Germany, came seasonably to support( the triumph of innovation. Otto Giiricke, a wealthy magistrate of Magdeburg, who amused his leisure by constructing pieces of mechanism, and instituting curious physical inquiries, finding that the belief in the impossibility of a vacuum, with other scholastic tenets, was on the gradual decline, had the boldness to conceive that the forming of a void was a task perhaps within the reach of human ingenuity. Fired with the idea of accomplishing what for ages had been deemed unattainable, he directed all his efforts to compass that end. In his first trials he failed,. as might be expected ; but, by perseverance, he was enabled to surmount every obstacle. Having filled a wooden cask with water, he attempted to ex tract this again, by means of a small sucking pump, introduced at the bottom of the cask, and worked vigorously by three stout men ; a hissing noise was heard like that of boiling water, the air entered from above through the interstices of the wood, and the water flowed out. The more effectually to exclude the air, he next took a smaller cask, with a sucker attached to it, and placed it within a larger one, hav ing filled up the space between them with water. On working the pump as before, the water was forced through the pores of the wood into the inner cask, but none was extracted by the action of the piston. Foiled in these attempts with wooden casks, he had recourse to a copper ball, to the under part of which he screwed an inclining sucker ; and, with this ap paratus, he at last succeeded in extracting the air. He continued the operation, till no farther portion of air was perceived to issue from the vent. On open ing the cock again, the air rushed into the cavity of the ball with violence; and the same effect took place, with scarcely any diminution of power, after an in terval of a day or two. The construction of the ma chine was afterwards rendered more perfect, by sub stituting a large inclined metal sucker,, with its joints secured by immersion in water.
Such was the origin of that most valuable addition to philosophical apparatus—the air-pump, which long retained its earliest rude and simple form on the Con tinent. By help of this new and powerful instrument, Giiricke was enabled to perform some interesting and very important experiments. One of these, which demonstrates in a very striking way the pressure of the atmosphere, has been since deservedly styled the Magdeburg Experiment. It was performed with two hollow copper hemispheres, closely fitted together, . and the air exhausted from their cavity. This sin gular experiment Giiricke had the honour of exhi biting, in the year 1654, before the princes of the empire and the foreign ministers, assembled at the diet of Ratisbon. The force of two teams, each consisting of a dozen of horses, made to pull in op posite directions, was found insufficient to sepa rate the hemispheres. It was now that the Bur gomaster of Magdeburg heard, for the first time, of Torricelli's great discovery, and the intelligence must have appeared quite delightful to him, who, by a path so different, had yet arrived at a similar conclusion.
After his return from this splendid assembly, Gliricke pursued at home various pneumatical re searches. He showed the diminished pressure of the atmosphere at an elevation above the surface, by means of a hollow ball fitted with a stop-cock ; hav ing carried this to a height, a portion of the contain ed air rushed out on turning the cock ; but when it was brought down again and opened, the same mea sure of air apparently flowed into its cavity. He actually weighed the air, by ascertaining, by a nice balance, the loss which a large bottle sustained on being exhausted, and found that air is 970 times lighter than water, a very near approximation, if al lowance were made for the residuum of air still left in the bottle. He was the first who proposed the Statical Balance for measuring the variations of atmospheric density, consisting of a hollow glass ball about a foot in diameter, hermetically sealed, and freely suspended in the air, to indicate by its different buoyancy the changes which take place in the gravity of the external fluid.
But Giiricke took great pleasure in a huge water barometer erected in his house. It consisted of a tube above thirty feet high, rising along the wall, and terminated by a tall and rather wide tube hermeti cally sealed, containing a toy, of the shapeof a man. The whole being filled with water, and set in a ba son on the ground, the column of liquid settled to the proper altitude, and left the toy floating on its sur face ; but all the lower part of the tube being con tolled under the wainscoting, the little image, or weather-mannikin, as he was called, made its ap-• pearanee only when raised up into view in fine weather: This whimsical contrivance, which receiv ed the name of anemoscope, or semper vivum, excited Among the populace vast admiration ; and the worthy magistrate' was in consequence shrewdly suspected by his townsmen of being too familiar with the of darkness.
The taste for experimental science was about this time introduced from the Continent into England.
The great struggle for the security of private rights had called forth the national energy, and its trium phant success had infused among all classes of men a spirit of boldness and enterprise most favourable to the reception of the new philosophy. The parlia mentary commissioners, by removing the more vio lentand bigoted members of the universities, con tributed, on the whole, to encourage a more liberal tone of thinking in those opulent seminaries. Near the close of the civil war, and during the vigorous administration df Cromwell, the philosophy by ex periment found some proselytes at last among the Oldsters of Oxford, where the masa of antiquated opinions had lain so long embalmed and protected by religious awe. A small association was there formed, for combining together the efforts of individuals in the prosecution of such inquiries ;' and the fruits of this mutual compact were afterwards visible in the composition of various philosophical works. But the Restoration, by which the nation, in a burst of considerate loyalty, surrendered the privileges which it had purchased with torrents of blood, threw the go vernment of the universities again into the hands of men decidedly hostile to the very shadow of improve ment. Experimental science withdrew to a more congenial soil, and sought shelter and support in the wider scope of the capital. The college founded by the munificence of Sir Thomas Gresham, for the be nefit of the citizens of London, though now unfortu nately sunk in absolute neglect, had the merit of first extending its protection to the pursuits of inductive philosophy. It produced a succession of professors, eminent in mathematical learning, which is so close ly allied with experimental research. A more exten sive association was accordingly formed in London, which regularly met at the apartments within the Exchange, and was afterwards, at the suggestion of Oldenburg, the resident from the city of Ham burg, and in imitation of the foreign academies constituted by charter into the Royal Society. Such was the humble beginning of that illustrious body, and such was all the countenance it received from a needy and profligate government. The institution, however, proved at first eminently useful, by the in fluence it had in directing the public opinion, and the shelter it afforded to experimental philosophy against the jealousy and declared hostility of the clerical and scholastic seminaries. The union of rank, or wealth, or talent, though still very limited in its range, bestowed a degree of lustre on the infant society, that was quite necessary for its defence against the attacks of ignorance, and the mining of bigotry.