Sir Benjamin, Count Rumford, a Thompson, well-known natural philosopher and political economist, was born on the 26th of March 1753, at Woburn, in the colony of Massachusetts. His father died while he was very young, and his mother marrying a second time, he was removed at an early age to the house of a stranger. He inherited only a small pittance from an uncle, who died soon after his father. A clergyman named Bernard showed him great kindness, and taught him some of the higher mathematics at an early age, so that at fourteen he was able to calculate and delineate an eclipse of the sun. He had been intended for some commercial employment, but he preferred the pursuit of literature in any form: he attended the lectures of Dr Williams, and afterwards those of Dr Winthrop the astronomer, at Harvard College; and while he was still a stripling, he was established in the temporary occupation of a village schoolmaster, hoping, however, for an early opportunity to engage in some more agreeable employment; and at nineteen, he was fortunate enough to obtain the hand of Mrs Rolfe of Rumford, now Concord, daughter of Mr Walker, a clergyman who had been employed with considerable credit in conducting some public business. For a year or two he lived retired and happy; but having obtained a commission of major in the militia from the governor of the province, together with some other distinctions of a civil nature, he was consequently led to adhere to the party of the Royalists; and he was soon obliged, by the success of the Independent forces, to take refuge at Boston, then occupied by the English troops. It was in November 1774 that he secretly quitted his residence, leaving his wife, whom he never saw again, and his infant daughter, who joined him twenty years after in Europe. He was employed to raise a regiment for the king's service; but when Boston was evacuated in 1776, he was sent with some important despatches to England. Here he soon acquired the confidence of Lord George Germaine, then colonial secretary of state, and was appointed secretary of the province of Georgia, though he never exercised the office; but he remained attached to that department of the public service.

In 1777 he commenced his career as an experimental philosopher, by employing his leisure hours, during a visit to Bath, in making some experiments on the cohesive strength of different substances; and upon his return to London, he communicated them to Sir Joseph Banks, with whom he formed an intimate acquaintance, which he kept up throughout the remainder of his life. In 1778 he was admitted a fellow of the Royal Society, and he made in that year his first experiments on gunpowder. In order to pursue these experiments, he went, in 1779, on board of the Victory, of 110 guns, commanded by his friend Sir Charles Hardy. He passed the whole campaign on board the fleet; and the results of the observations which he then made furnished the materials of a chapter which he contributed to Stallart's Treatise on Naval Architecture. He added to it a code of signals for the navy, which was not published. In 1780 he was appointed under-secretary of state, and he was constantly employed, for some little time, in the office on the business of the war. He succeeded, by means of his American friends and agents, in raising a regiment of cavalry, called the King's American Dragoons, of which he was appointed lieutenant-colonel commandant; and this success induced him to go to America to serve with it. At Charleston he was intrusted with the command of the remains of the cavalry of the British army. He speedily restored the discipline of the corps, and gained its confidence and attachment: he often led it against the enemy, and frequently with considerable success. He proceeded, in 1782, to New York, where he assumed the command of his own regiment, having received the colours from the hand of Prince William Henry. In the autumn, Gene- Thompson, ral Clinton was succeeded by Sir Guy Carlton, whose friendship and confidence he speedily obtained. His regiment was recruited from the fragments of several others, and he was sent for the winter to Huntingdon in Long Island. In 1783 he was chosen to conduct the defence of Jamaica, which was then threatened by the enemy; but the general peace superseded the necessity of the intended expedition.

After his return to England, he made great efforts in the cause of the Royalist officers, and he was successful in persuading the ministry to make a proper provision for them. He was himself raised to the rank of colonel, upon the recommendation of General Carlton, only two years after his appointment as lieutenant-colonel. He had acquired a strong predilection for a military life, and was desirous of being sent with his regiment to the East Indies; and, when the regiment was reduced, he wished to serve with the Austrians in a war which was then meditated against the Turks. With this view he left England in September 1783, and, on his passage to Boulogne, he had an agreeable shipmate in the person of Gibbon the historian, who did justice to his merits as a "soldier, philosopher, and statesman." At Strasbourg, his appearance on the parade in his uniform excited the attention of the late king of Bavaria, then Prince Maximilian of Deux Ponts, who invited him to his table, and being delighted with the accuracy and extent of his military knowledge, gave him a strong recommendation to his uncle, then elector; and instead of a day or two, as he had intended, he stayed a fortnight at Munich. He was also very cordially received at Vienna, and passed a part of the winter there; but the war against the Turks not taking place, he returned by Venice and the Tyrol to Munich, where he arrived in the winter of 1784; and being formally invited by the elector to enter his service, he went to London to ask leave to accept the proposal; and it was granted him, together with the honour of knighthood. On his return to Bavaria, he was made a colonel of cavalry, and aide-de-camp-general to the elector. The first four years of his residence at Munich were principally employed in acquiring information, and in preparing his plans of reform; and in the meantime he continued his physical researches. He made his first experiments on heat in 1786, during a journey to Mannheim. In 1785 he was made chamberlain to the elector, and member of the academies of Munich and of Mannheim; in 1786 he received from the King of Poland the order of St Stanislas; in 1787 he took a journey to Berlin, and was made a member of the Academy of Sciences of that city; in 1788 he was appointed major-general of the Bavarian cavalry, and privy counsellor of state; and he was placed at the head of the war department, in order to pursue his plans for the improvement of the army. The Elector Leopold likewise conferred upon him the title of count of the holy Roman empire. Sir Benjamin Thompson was accordingly henceforth known as Count Rumford, the original title of the residence of his wife in America.

It was in 1789 that he established the House of Industry at Mannheim. He founded also the Military Academy of Munich; he improved the military police of the country; he formed schools of industry for the wives and children of the soldiers; and he embellished the city by a new arrangement of the public gardens. The House of Industry at Munich, which he has described at large in his Essays, was founded in 1790; and from this period may be dated the total abolition of mendicity in Bavaria. His exertions were rewarded by the rank of lieutenant-general of the Bavarian armies, and by a regiment of artillery. His health having suffered from constant application, he obtained permission to take a journey into Switzerland and Italy, and he returned to Bavaria in 1794. He had a severe illness at Naples, and he was not sufficiently recovered, upon his return, to resume his active duties; but he employed himself in writing the first five of his Essays. In 1795 he came to England in order to publish the Essays, and in hopes of exciting the public attention to the importance of attempting a similar reform among the lowest orders in Great Britain. He went to Dublin in 1796, to pay a visit to Lord Pelham, afterwards Earl of Chichester, then secretary of state for Ireland; and he was of essential service in the arrangement of several of the public institutions of that country. He was made a member of the Royal Irish Academy, and of the Society for the Encouragement of Arts; and, after having left the country, he received the public thanks of the grand jury of the county of Dublin, and of the lord mayor of that city, as well as of the lord-lieutenant at the head of the government. Upon his return to London, he superintended some improvements at the Foundling Hospital, and presented several models of machines and implements to the Board of Agriculture; and he established two prizes, for discoveries relating to heat and light, by placing two sums of L1,000 in the British and in the American funds, to be adjudged biennially, for Europe by the Royal Society of London, and for America by the American Academy of Sciences.

He was recalled to Bavaria by the exigencies of the moment, which were such as to cause the elector to take refuge in Saxony, General Moreau having advanced with his army to the confines of Bavaria. After the battle of Friedberg, Count Rumford was left in command of the Bavarian army, with instructions to act according to his discretion under the circumstances that might occur; and his firmness was such as to prevent either the Austrians or the French from entering Munich. On the elector's return, he was placed at the head of the department of the general police of Bavaria. His exertions in this office were such as to impair the state of his health, and, by way of an honourable retirement, he was sent to London in the capacity of envoy-extraordinary and minister-plenipotentiary; but being a subject of the king of Britain, he was judged incapable of being received as the diplomatic agent of a foreign court, and he therefore continued to live in England as a private individual. He was very active about this period in projecting and superintending the establishment of the Royal Institution of Great Britain, which was more particularly intended for the application of science to the conveniences and comforts of civil and domestic life, but which has been no less successful in giving opportunity and facility to some of the most refined researches in chemistry and natural philosophy that have distinguished the age, than in serving as a medium for making the treasures of science accessible to the less studious part of the public, and as a model for a variety of other similar undertakings in different parts of the world.

Count Rumford was soon afterwards officially invited to America by the government of the United States, with an offer of an honourable establishment in a public situation; but he considered it as inconsistent with his engagements in Europe to accept the proposal. In the autumn of 1800, when he went to Scotland, a visit of ceremony was paid to him by the magistrates of Edinburgh. He was consulted respecting the abolition of mendicity, and the measures which he recommended were speedily executed with complete success. He was made an honorary member of the Royal Society and of the Royal College of Physicians of Edinburgh; and he received a gold snuff-box as a compliment for his assistance in reforming the culinary establishment of Heriot's Hospital.

After so active and diversified a career, it was not to be expected that he would be satisfied with the monotony of a permanent residence in London. He was so accustomed to labour for the attainment of some object, that when the Count Rumford's first publication appears to have been the chapter on "Marine Artillery" which he furnished to Stalker's Treatise on Naval Architecture, 1780. New Experiments on Gunpowder, with the Description of an Epronette, Phil. Trans. 1781, p. 230. The effect of the powder on the ball was measured by the recoil of the piece, with a correction made from the recoil when the piece was empty. It was observed to be sooner heated when fired without ball than with it. The force of the powder is made at least 1300 atmospheres, upon Robins's principles. New Experiments on Heat, Phil. Trans. 1786, p. 273. These experiments relate principally to the conducting powers of various substances for heat; but the results are unavoidably complicated with the effects of radiation, in consequence of which a vacuum is supposed to possess a conducting power more than half as great as that of common air. Experiments on the Production of Dephlogisticated Air from Water with various Substances, Phil. Trans. 1787, p. 84. These experiments tend to show that the air obtained by Priestley and Ingenhousz, from plants under water, was derived rather from the water itself than from the substances immersed in it. Experiments made to determine the Positive and Relative Quantities of Moisture absorbed from the Atmosphere by various Substances, p. 240. He finds that wool is more absorbent of moisture than any other substance compared with it; and hence explains the supposed advantage of woollen worn next the skin. Experiments on Heat, Phil. Trans. 1792, p. 48. The author attributes the effects of loose substances in obstructing the passage of heat, to their attraction for air, and to their impeding its circulation; and he supposes this to be the only manner in which elastic fluids communicate heat. Account of a Method of Measuring the Comparative Intensity of Light emitted by Luminous Bodies, Phil. Trans. 1794, p. 67. Letter announcing the Donation for a Prize Medal, Phil. Trans. 1797, p. 215. Experiments to determine the Force of Fired Gunpowder, p. 272. This force he supposes to amount to between 20,000 and 50,000 atmospheres, instead of 10,000, as Bernoulli computed it; but he makes a great mistake in supposing that the whole of the water which can possibly be contained in the gunpowder would be sufficient to furnish as much steam as would be required, since steam, under a pressure of 20,000 atmospheres, must be considerably more dense than water itself. Inquiry concerning the Source of the Heat excited by Friction, Phil. Trans. 1798, p. 89. The capacity of the chips of iron afflamed by friction in being a cannon, was found not to differ from that of the iron in its original state; hence it is inferred that the heat could not have been furnished by them, and that it must probably have been generated. Mr Haldal's attempt to reproduce the experiment under circumstances still more decisive, and Sir Humphry Davy showed that two pieces of ice rubbed together, in a room below the freezing temperature, would melt each other. Inquiry concerning the Chemical Properties that have been attributed to Light, p. 449. He attributes these properties to the effect of an intense heat confined to a small space; but the latter experiments on the chemical effects of the spectrum are sufficient to supersede this opinion. An Account of a Curious Phenomenon observed on the Glass of Chamonix, with some observations on the Propagation of Heat in Fluids, Phil. Trans. 1804, p. 23. An effect depending on the expansion of water in cooling near the freezing-point. Concerning the Nature of Heat, and the Mode of its Communication, p. 77. He conjectures that heat is a positive quality, capable of being propagated by radiation. Several of these memoirs were reprinted under the title of Philosophical Papers, vol. I, Lond. 1802, Svo. The Essays constitute four vols., Svo, Lond. 1795-1800; reprinted 1800, in French, 2 vols., Svo, Genev. 1799. Recueil de Rapports... sur les Soupes, Par. 1801. They are eighteen in number. 1. "Account of an Establishment for the Poor at Munich," in Ital., Svo, Venecia, 1798. 2. "On Establishments for the Poor in general." 3. "Of Food, and of Feeding the Poor." 4. "Of chimney Fire-places." 5. "Account of several Public Institutions formed in Bavaria." 6. "On the Management of Fire, and the Economy of Fuel." 7. "On the Propagation of Heat in Fluids, extending to Liquids the Doctrine which he had before advanced respecting Elastic Fluids." 8. "On the Propagation of Heat in various Substances," Phil. Trans. 9. "Experimental Inquiry concerning the Source of Heat excited by Friction." 10. "On Kitchen Fire-places and Kitchen Utensils." 11. "On Chimney Fire-places." 12. "On the Salubrity of Warm Rooms in Cold Weather." 13. "On the Salubrity of Bathing, and the Construction of Warm Baths." 14. "Supplementary Observations on the Management of Fires." 15. "On the Use of Steam for Transporting Heat." 16. "On the Management of Light in Illumination, with an Account of a new Portable Lamp." 17. "On the Source of the Light manifested in the Combustion of Inflammable Bodies." 18. "On the excellent Qualities of Coffee, and the Art of Thomson, making it in Perfection." There are several little papers on Steam Kitchens, on the Strength of Soft Materials, and on some other similar subjects, in the first numbers of the Journals of the Royal Institution, Svo., Lond., 1800. The series of investigations relating to Heat and Light, which Count Rumford began to communicate to the Royal Society, were continued, and rather more fully detailed, in several of the volumes of the Memoirs of the Institute, Mathematical Class—in which they were, of course, admitted as the productions of a foreign associate. The first of these is in the sixth volume (4to, Par. 1506, p. 71), containing a " Description of a new Instrument—a Thermoscope, or a Differential Thermometer, resembling that of Leslie." The 21, p. 74, " Researches on Heat; showing the Effect of the Difference of Surface on Radiation," 3d, p. 88, " Further Experiments; on the Effect of blackening the Surface," 4th, p. 97, " Researches continued; on the different Properties of Bodies with respect to Radiation and to Conducting Power," 5th, p. 106, " Further Researches; some good Experiments on the Passage of Heat through Solids," 6th, p. 123, " Experiments on the Heat of the Solar Rays; which was found not to be affected by their convergence or divergence, though having met in a focus and crossed each other," 7th, vol. vii. I., 1806, p. 78, " Remarks on the Temperature of Water at the Maximum of Density, making it 41° of Fahrenheit, or 5° centigrade," Phil. Trans., 1804, 8th, vol. viii. I., 1807, p. 223, " On the Dispersion of the Light of Lamps by Screens of Ground Glass, Silk, and so forth, with a Description of a new Lamp," 9th, p. 249, " On the Cooling of Liquids in Vases of Porcelain, gilt and not gilt; showing the utility of gilding them externally, with some good reasoning on the nature of heat." He was latterly engaged in composing a work on the Nature and Effects of Order, which he never completed, although no person was better qualified to write on the subject.

William, a very industrious Irish naturalist, was born at Belfast on the 2d of November 1805. He first joined his father as a linen-merchant; but gradually acquiring a taste for natural history, he gave up this business in 1832, and devoted himself henceforward to his favourite study. The minerals, plants, and animals of Ireland, all received his attentive observation. After contributing numerous small papers to the Zoological Society of London, he, in 1840, gave a very excellent " Report on the Fauna of Ireland—Division Vertebrata." Many of his papers are likewise published in the Ray Society's Bibliography and the Annals of Natural History. He published his great work on the Natural History of the Birds of Ireland, in 3 vols., 1849–51. After his death, which occurred in 1852, his Natural History of Ireland was published in 1856. Thompson was a member of all the notable societies of his native country, as well as of many of foreign nations. Although a man of no pre-eminence, his devotion to his peculiar subject, and his quick sagacity in detecting the more superficial characteristics of nature, rendered him eminent in the walk which he chose.