GLASGOW College. 221 "the wily ecclesiastic had seized upon and destroyed the liberties of the town of Glasgow." The general claim to do as they pleased in the city, it is true, had been abandoned; but over the area occupied by their buildings and gardens, the power of the college council remained as absolute as ever. Into this, as an asylum, Watt was admitted; and by the kind offices of some of the professors, a room within the sacred precincts was allotted to him, in which henceforth he could transact his business, without even a fear of molestation from the sturdiest deacon of the corporation. It was here, some time in 1759, that his attention was first directed to the subject of steam-engines, by a student, who although young, was distinguished for his attainments in the geometry of the ancients. The idea of applying steam to move carriages, was thrown out by Mr. Robison*, but *JOHN ROBISON, LL.D., was the younger son of a merchant who had retired from business, and lived at Baldernock, Stirlingshire, where he was born in 1739. He was intended for the church, but in the course of his studies he imbibed an aversion to it as a profession. He accompanied, as a tutor, the son of Admiral Knowles, in the expedition which co-operated in the conquest of Quebec; and on some promises of promotion, he went with his former pupil to Portugal. On his return to England, he was selected by the Board of Longitude to proceed to the West Indies, to observe the famous time-keeper, for which Harrison claimed the national reward of twenty thousand pounds. Being disappointed at his return of the expected pursership, he retired to Glasgow, and succeeded Dr. Black as lecturer on chemistry. His patron, Admiral Knowles, having received a high naval office from the court of Russia, Robison accepted of his invitation to accompany him, and act as his secretary. By the admiral's influence, he was nominated Inspector of Marine Cadets at Cronstadt, an appointment which he gave up, on being elected to the Professorship of Natural Philosophy in the University of Edinburgh, where he spent the remaining thirty years of his life, and continued his literary labours without intermission. The most important of these was a 222 PAPIN'S DIGESTER. he soon afterwards leaving college, and going with the expedition which reduced Canada, the scheme was given up. After an interval of two years, Watt attempted (1761-62) some experiments with a Papin's digester, (figure marked WATT L.) and by fixing to its lid a brass syringe, having a solid piston, he formed a kind of steam-engine. The vapour from the boiler, a, was admitted to the under side of the piston, c, by a cock, o, which also opened or closed the communication with the atmosphere. When steam flowed from the boiler into the cylinder the piston was raised up, and lifted a weight, i, with which it was loaded; and the steam from the boiler being then interrupted, and a communication with the atmosphere opened, the piston fell to the bottom of the syringe*. An impression of danger from bursting the boiler, the difficulty which it was obvious would be experienced to make the joints steam-tight, and a waste of steam taking place, from no vacuum being made to assist the rise of the piston, made him not only relinquish the thought of a machine on this principle, but to suspend his experiments. series of papers which have been lately collected into four volumes, under the title of Elements of Mechanical Philosophy, a work of great merit. This contains an excellent history of the steam-engine, nearly to the period of the Doctor's death (1805), to which Mr. Watt added notes, giving a narrative of the steps by which he was led to his great improvements. "Doctor Robison's person is described as handsome, and his countenance as prepossessing. He was a good linguist, an excellent draughtsman, and an accomplished musician, His conversation was always energetic and interesting, and sometimes poetical. His mind was imbued with the genuine spirit of the philosophy he taught, and nobly elevated above the mean jealousies of rival ambition." *The figure is copied from Leupold's Theatrum Machinarum, Fig. 27, vol. iii., published thirty-five years before the trial in the text. PROFESSOR ANDERSON. 228 At the lapse of other two years the subject was again presented to his observation, by a model of an engine constructed on Newcomen's principle, which Professor Anderson* had sent him to repair. * JOHN ANDERSON, A.M., F.R.S., F.A.S., a distinguished Professor of Mechanical Philosophy in the University of Glasgow, was born at Roseneath, Dumbartonshire, in 1726. His father, who was minister of the parish, died while he was very young, but he was brought up and carefully educated by an aunt. In 1745, when Stirling was besieged by the Pretender, he acted as an officer in the regiment which was formed by the inhabitants to assist in its defence; and from this circumstance he imbibed a strong predilection for the military art, and made considerable progress in the study of fortification. He planned and superintended the works erected for the defence of the town of Greenock against the French sea-captain Thurot. "He invented a sixpounder field-piece, the recoil of which was stopped by the condensation of common air within the body of the carriage;" this being rejected under rather unpleasant circumstances by the Duke of Richmond, then Master-General of the Ordnance, its inventor in disgust went to Paris, and presented it to the National Convention. The legislators, with more tact than "the patriotic Duke," accepted his offering, and ordered his model to be hung up in their hall, inscribed as "the gift of science to liberty." And they pleased the Professor by permitting him to make experiments with it, at his own expense, in the neighbourhood of Paris. During his residence there, Louis XVI. was brought from Varennes, and the Professor is said to have stood on the altar of liberty with the Bishop of Paris, and sung Te Deum when the unfortunate king took an oath to the constitution. And when the Emperor of Ger. many established a line of troops on his frontiers, to guard against the introduction of French principles and newspapers, he suggested the plan of making small balloons of paper, varnished with boiled oil, and filled with inflammable air, to which the dreaded manifestoes might be tied. When the wind was favourable for Germany, these revolutionary heralds were sent off, and descending in that country were picked up by the people. They carried a small flag or streamer, bearing an inscription of which the following is a translation:"O'er hills and dales and lines of hostile troops I float majestic, Bearing the laws of God and nature to oppressed men, 224 PROFESSOR ANDERSON. At this time he knew nothing of the mechanism except from the descriptions given by Belidor and Desaguliers, and their illustrations were in many points obsolete, and in others contradictory and inconsistent. When he set, however, about repairing the model, as a mere mechanician, he found that the In turning from these vagaries, which he lived long enough to regret, he is presented to us in the character of a warm and disinterested lover of his country, an ornament to it by his talents and genius, and entitled to its grateful remembrance for being the first who afforded the means of instruction in philosophy to the working classes. He visited workshops, to draw from mechanic operations illustrations of the doctrines he taught in his lectures; and he invited artisans to attend his discourses, to hear an explanation of the principles on which their manual operations depended. These familiar and popular lectures he delivered twice a week during the college session, for many years before his death, and he made them permanent, by bequeathing nearly his whole fortune for the endowment of an institution in which philosophy was to be taught in its application to the arts, in a manner adapted to the comprehension of the artisan. This establishment has lately acquired great celebrity, as the parent of Mechanics' Institutions. Doctor Garnett was the first who, under the founder's will, continued his lectures for a few seasons. Doctor Birkbeck next gave two or three courses of lectures, but to Doctor Ure it appears is mainly due the honour of giving form and stability to the institution; who has through good and adverse times, for twenty years, devoted his labours to promote its usefulness and prosperity. "Professor Anderson was in the custom of delivering his lectures extempore, a practice which is now but little followed. As a popular lecturer, he was unrivalled. His manner was easy and graceful, his command of language unlimited, and the skill and success with which his manifold experiments were performed, could not be surpassed. His free and independent mind was exhibited in every action of his life; and enthusiastic in his profession, his whole ambition and happiness consisted in making himself useful by the dissemination of knowledge. He was the author of some detached works of merit, and of numerous papers in the various periodical works of the time. He died at Glasgow in 1796."-Glasgow Mechanic's Magazine, vol. iii., p. 4. boiler (about nine inches in diameter) although sufficiently large when compared with those used in practice, could not supply steam fast enough for the two-inch cylinder which had a six-inch stroke, and although the vacuum was very imperfect, an enormous quantity of injection-water was required to produce it. He rightly attributed this to the cylinder of the model exposing a greater surface in proportion to its capacity than the larger cylinders, and the cylinder of brass cooled faster than the cast-iron ones of working engines. Operating with a still more imperfect vacuum, the boiler supplied steam to move the piston regularly, and the injection-water required was moderate. Thinking to diminish the waste of steam by using a material which would cool slower than brass, he made a cylinder of wood*, (six inches diameter and twelve inches stroke,) soaked in linseed oil and baked to dryness. This was not only objectionable on account of its less durability, but it condensed more steam in proportion than working engines. In fact, the cylinder itself heated the water which it contained, and produced vapour, which in part resisted the pressure of the atmosphere, and thus diminished the power of the engine. A better vacuum was easily produced, by * In an engine Brindley erected at Newcastle-under-Lyne, he introduced wooden cylinders, made in the manner of coopers' ware, instead of iron ones, as being cheaper and more easily managed in the shafts. He also substituted wood for iron in the chains which worked at the end of the beam. He had formed designs of other improvements, but he was dis couraged by obstacles thrown in his way from proceeding with them. In another instance he surrounded his metal cylinders with a wooden case, and the interval was filled with light wood ashes, and by this and using no more injection than was necessary for the condensation, he reduced the waste of steam to almost one-half. Rees's Cyclo. vol, xxxiv. Art. STEAM-ENGINE. |