Heroes of Science: Physicists. Garnett William
Читать онлайн книгу.
could not be so otherwise, were confuted by a decree from Rome; his highness the Pope, it seems, presuming, and that justly, that the infallibility of his chair extended equally to determine points in philosophy as in religion, and loth to have the stability of that earth questioned in which he had established his kingdom."
Having visited Rome, he at length returned to France, and was detained at Marseilles, awaiting a remittance from the earl to enable him to continue his travels. Through some miscarriage, the money which the earl sent did not arrive, and Robert and his brother had to depend on the credit of the tutor to procure the means to enable them to return home. They reached England in the summer of 1644, "where we found things in such confusion that, although the manor of Stalbridge were, by my father's decease, descended unto me, yet it was near four months before I could get thither." On reaching London, Robert Boyle resided for some time with his sister, Lady Ranelagh, and was thus prevented from entering the Royalist Army. Later on he returned for a short time to France; visited Cambridge in December, 1645, and then took up his residence at Stalbridge till May, 1650, where he commenced the study of chemistry and natural philosophy.
It was in October, 1646, that Boyle first made mention of the "invisible college," which afterwards developed into the Royal Society. Writing to a Fellow of Magdalen College, Cambridge, in February, 1647, he says, "The corner-stones of the invisible, or, as they term themselves, the philosophical college, do now and then honour me with their company." It appears that a desire to escape from the troubles of the times had induced several persons to take refuge in philosophical pursuits, and, meeting together to discuss the subjects of their study, they formed the "invisible college." Boyle says, "I will conclude their praises with the recital of their chiefest fault, which is very incident to almost all good things, and that is, that there is not enough of them." Dr. Wallis, one of the first members of the society, states that Mr. Theodore Hooke, a German of the Palatinate, then resident in London, "gave the first occasion and first suggested those meetings and many others. These meetings we held sometimes at Dr. Goddard's lodging, in Wood Street (or some convenient place near), on occasion of his keeping an operator in his house, for grinding glasses for telescopes and microscopes, and sometimes at a convenient place in Cheapside; sometimes at Gresham College, or some place near adjoining. Our business was (precluding theology and State affairs) to discourse and consider of philosophical inquiries, and such as related thereunto; as physic, anatomy, geometry, astronomy, navigation, statics, magnetics, chemics, mechanics, and natural experiments, with the state of these studies as then cultivated at home and abroad. About the year 1648-49 some of us being removed to Oxford, first Dr. Wilkins, then I, and soon after Dr. Goddard, our company divided. Those in London continued to meet there as before, and we with them when we had occasion to be there. And those of us at Oxford, with Dr. Ward, since Bishop of Salisbury, Dr. Ralph Bathurst, now President of Trinity College in Oxford, Dr. Petty, since Sir William Petty, Dr. Willis, then an eminent physician in Oxford, and divers others, continued such meetings in Oxford, and brought those studies into fashion there; meeting first at Dr. Petty's lodgings, in an apothecary's house, because of the convenience of inspecting drugs and the like, as there was occasion; and after his remove to Ireland (though not so constantly) at the lodgings of Dr. Wilkins, then Warden of Wadham College; and after his removal to Trinity College in Cambridge, at the lodgings of the Honourable Mr. Robert Boyle, then resident for divers years in Oxford. These meetings in London continued, and after the king's return, in 1660, were increased with the accession of divers worthy and honourable persons, and were afterwards incorporated by the name of the Royal Society, and so continue to this day."
Boyle was only about twenty years of age when he wrote his "Free Discourse against Swearing;" his "Seraphic Love; or, Some Motives and Incentives to the Love of God;" and his "Essay on Mistaken Modesty." "Seraphic Love" was the last of a series of treatises on love, but the only one of the series that he published, as he considered the others too trifling to be published alone or in conjunction with it. In a letter to Lady Ranelagh, he refers to his laboratory as "a kind of Elysium," and there were few things which gave him so much pleasure as his furnaces and philosophical experiments. In 1652 he visited Ireland, returning in the following summer. In the autumn he was again obliged to visit Ireland, and remained there till the summer of 1654, though residence in that country was far from agreeable to him. He styled it "a barbarous country, where chemical spirits were so misunderstood, and chemical instruments so unprocurable, that it was hard to have any hermetic thoughts in it." On his return he settled in Oxford, and there his lodgings soon became the centre of the scientific life of the university. Boyle and his friends may be regarded as the pioneers of experimental philosophy in this country. To Boyle the methods of Aristotle appeared little more than discussions on words; for a long time he refused to study the philosophy of Descartes, lest he should be turned aside from reasoning based strictly on the results of experiment. The method pursued by these philosophers had been fully discussed by Lord Bacon, but at best his experimental methods, though most complete and systematic, existed only upon paper, and it was reserved for Boyle and his friends to put the Baconian philosophy into actual practice.
It was during his residence at Oxford that he invented the air-pump, which was afterwards improved for him by Hooke, and with which he conducted most of those experiments on the "spring" and weight of the air, which led up to the investigations that have rendered his name inseparably connected with "the gaseous laws." The experiments of Galileo and of Torricelli had shown that the pressure of the air was capable of supporting a column of water about thirty-four feet in height, or a column of mercury nearly thirty inches high. The younger Pascal, at the request of Torricelli, had carried a barometer to the summit of the Puy de Dome, and demonstrated that the height of the column of mercury supported by the air diminishes as the altitude is increased. Otto von Guericke had constructed the Magdeburg hemispheres, and shown that, when exhausted, they could not be separated by sixteen horses, eight pulling one way and eight the other. He was aware that the same traction could have been produced by eight horses if one of the hemispheres had been attached to a fixed obstacle; but, with the instincts of a popular lecturer, he considered that the spectacle would thus be rendered less striking, and it was prepared for the king's entertainment. Boyle wished for an air-pump with an aperture in the receiver sufficiently large for the introduction of various objects, and an arrangement for exhausting it without filling the receiver with water or otherwise interfering with the objects placed therein. His apparatus consisted of a large glass globe capable of containing about three gallons or thereabouts, terminating in an open tube below, and with an aperture of about four inches diameter at the top. Around this aperture was cemented a turned brass ring, the inner surface being conical, and into this conical seat was fitted a brass plate with a thick rim, but drilled with a small hole in the centre. To this hole, which was also conical, was fitted a brass stopper, which could be turned round when the receiver was exhausted. By attaching a string to this stopper, which was so long as to enter the receiver to the depth of two or three inches, and turning the stopper in its seat, the string could be wound up, and thus objects could be moved within the receiver. The tube at the bottom of the receiver communicated with a stop-cock, and this with the upper end of the pumpbarrel, which was inverted, so that this stop-cock, which was at the top of the barrel, took the place of the foot-valve. The piston was solid, made of wood, and surrounded with sole leather, which was kept well greased. There being no valve in the piston, it was necessary to place an exhaust-valve in the upper end of the cylinder. This consisted of a small brass plug closing a conical hole so that it could be removed at pleasure. The construction of the cylinder was, therefore, similar to that of an ordinary force-pump, except that the valves had to be moved by hand (as in the early forms of the steam-engine). The piston was raised and depressed by means of a rack and pinion. The pumps could be used either for exhausting the receiver or for forcing air into it, according to the order in which the "valves" were opened. If the stop-cock communicating with the receiver were open while the piston was being drawn down, and the brass plug removed so as to open the exhaust-valve when the piston was being forced up, the receiver would gradually be exhausted. If the brass plug were removed during the descent of the piston, and the stop-cock opened during its ascent, air would be forced into the receiver. In the latter case it was necessary to take special precautions to prevent the brass plate at the top of the receiver being raised from its seat. All joints were made air-tight with "diachylon," and when, through the bursting of a glass bulb within it, the receiver became cracked, the crack was rendered air-tight by the same means.