Up to his eleventh year young Thompson attended the village school, and learned reading, writing, and arithmetic for several hours in the day, devoting his play-hours to the more congenial employment of making drawings of his companions' faces, which he often caricatured unmercifully, constructing various toys, and in experimenting in a small way in natural philosophy.

These amusements did not meet the approval of his family, whose idea of life was quite different. The experiments and inventions showed a taste for something beyond the ordinary routine of a farmer's life, and Benjamin's fancy for exploring the unknown was not encouraged. Happily for him, he was sent in his eleventh year to an adjoining village in order to be under the care of a very excellent teacher, and as his interest in things outside of the usual line increased daily by contact with the mind of his teacher, it was decided by his friends to give up all hopes of making the boy a farmer, and apprentice him to some trade. When he was thirteen years old, therefore, he was sent to Salem to learn to be a merchant, and here he met friends who encouraged his love for knowledge, and aided him in the most substantial way. His duties as a clerk were faithfully performed, but they only seemed to him to be the necessary means toward something higher. All his leisure time was spent either in boyish frolicking, or in studying subjects quite unconnected with the mercantile life, and both these circumstances often caused some of his friends to shake their heads gravely over his refusal to regard trade as the most serious and respectable business of life.

Their disapproval, however, did not in the least affect the spirits of Benjamin, who was always ready for fun, sometimes even enlivening his dull business by playing on the violin, and at others busily engaged over the question of making fireworks which he and his friends were to send off at the first possible opportunity. A little note-book which he kept at this time shows a curious mixture of caricatures, drawing of boats, bottles, tomahawks, human bones, bars of music, and pistols, interspersed with recipes for making rockets, stars, serpents, and other fireworks, illustrated with drawings in ink.

These pursuits, however, did not prevent attention to more serious subjects, and during the first years of his apprenticeship Benjamin made such good use of his time, and of his of studying with an older friend, that before he was fifteen he had a fair knowledge of algebra and geometry, and had made such progress in astronomy as to be able to calculate an eclipse so accurately that it occurred within a few seconds of the computed time.

Trade could not long hold the attention of such a mind, and when he was eighteen Benjamin left his master and began the study of medicine, supporting himself in the meantime by teaching school. He made considerable progress in his new business, and was so successful as a teacher that he was invited to take charge of a school at Concord, then called Rumford.

And it was here that events happened which entirely changed his life, and resulted in his devoting his great powers to science. Shortly after his arrival at Concord he married the daughter of one of the most prominent men of the place, coming by this means into the possession of a large estate; but hardly had he settled down to the business of managing his new property before he was compelled to leave the town as a fugitive. His marriage had taken place in October, 1774, and in November of the same year he was accused of sympathy with the English Government, and his life was threatened by his enraged townsmen, who were in the full tide of anger against the mother country.

Although at the trial afterward he was pronounced innocent of the charges laid against him, he never recovered the faith of his countrymen, and was always subject to their suspicions, which were perhaps not wholly unjust when it is considered that in 1776 he went to London and took service under the British Government.

He now began to make experiments in gunpowder, and on the making of cannon and the measurement of the velocities of bullets, and subsequently went on a cruise in order to give his theories a final test. He thus acquired a taste for military life, and after a short trip to America, he returned to Europe in 1783, hoping to serve in the Austrian campaign against the Turks. He was always so thoroughly in earnest that if Austria had begun the expected war it is probable that Thompson's career might have been wholly directed to military glory; but, fortunately for science, he met about this time an old lady, the wife of one of the Austrian generals, whose influence led him to take other views of life, and convinced him that a life devoted to the relief of mankind was of infinitely more value than any honor gained on the field of battle.

Soon after this he was invited to Munich by the Duke of Bavaria, who urged him to enter his service, and from this time his life was one of ceaseless activity. Munich, in common with other European cities, was at that time subjected to the most incompetent public service, and the state of affairs in the capital was common throughout the country.

Thompson was appointed colonel of a cavalry regiment, and aide-de-camp to the duke, who also gave him a palace to live in, and a military staff and corps of servants. But his magnificent style of living, and the honor paid him as the friend and adviser of the duke, did not in the least interfere with the plans he had formed for the improvement of Bavaria. Thriftlessness, abuse of power by the priesthood, discontent in the army, and neglect of the resources which might bring comfort and wealth were among the evils that Thompson set about finding remedies for, and his practical mind and great executive ability soon brought about the needed reformation.

The discontent of the army had its source in real grievances. The soldiers were taken from their homes and scattered all over the country, leaving the fields untilled and the manufacturing industries destroyed while they were serving in the army, which had such a demoralizing effect upon them as to unfit them for useful labor when their time of service had expired. Their pay was miserable, their quarters uncomfortable, and the comfort of their families entirely overlooked.

Thompson's remedy for this evil was radical and prompt. He had permanent garrisons made, so that the soldiers from the different districts might remain near their homes; he the drill and discipline, giving the soldiers much more time at their own disposal, and this time could either by employed in the public works, or in manufacturing different articles from the raw material furnished them, or in the cultivation of the little gardens which were the property of every soldier, every one of the different occupations being a source of added income to the privates, who had hitherto been looked upon only as the slaves of the officers.

Besides this, the barracks were made clean within and without, the soldiers were better clothed and better fed, there were schools established for their children, and when it was absolutely necessary for the troops to be garrisoned at great distances from home, long furloughs were allowed, so that the men might attend to the agricultural and manufacturing interests that had sprung up. The effect of the new system was magical. Discontent disappeared from the army, and the soldier was transformed from an indolent, fault-finding, and dissatisfied attaché  of the officer, to a self-supporting and self-respecting citizen. Little sprang up all over the country, where the soldier, clothed in the working suit furnished him by the State, might be seen planting seeds; and many vegetables, among them the potato, which had hitherto been almost unknown in Bavaria, from this time became staple articles of food. The reform of the army was followed by another improvement of equal value.

The evils of a standing army, the dearth of manufactures and the neglect of agriculture, had all combined to bring about a state of affairs among the working classes as demoralizing as the condition of the soldiers. The whole of Bavaria was overrun with people who had no trade, no home, no duties, and, worst of all, who considered that they had a right to demand a living of their more self-respecting and independent neighbors.

Beggars abounded everywhere, and society was divided into two factions, one representing the respectable element, and the other the disreputable hordes who roved about the country, feared on account of their numbers and defiant of all control. Not only did the natives take advantage of this condition, but beggars swarmed in from adjoining countries and found cordial welcome from the depraved vagabonds who had learned that numbers meant power.

Beggary was in fact but a kind of freebooting, and the beggars considered themselves members of a respectable and worthy fraternity whose rights must be maintained. And they found this an easy matter, as their crimes had made them a terror to the country, and the civil authorities had come to look upon the case as almost hopeless. The highways were lined with beggars who demanded alms from all travellers; stores, houses, workshops, and churches were entered and money extorted by threats; and the husbandman and merchant had alike learned to consider the beggar's portion as a necessary detail in the year's expenditures.

In the cities things were even worse. In Munich the whole city was divided off into districts, each being under the control of certain bands, which were governed by a code of unwritten but not the less stringent laws. This nuisance was attacked by Thompson in the same spirit which had actuated him in his work for the army. He declared that the government owed not only protection to the honest classes, but moral responsibilities to the beggars themselves, and he proposed to rid the country of begging by turning the offenders into self-supporting citizens. Such a proposal from one less practical and less powerful would have met with no response. But Thompson's regeneration of the army had proved his administrative powers, and the authorities of Munich gladly promised him all the aid he could desire.

He ordered the city to be divided into districts, and every dwelling, from palace to hovel, to be numbered. Each district was furnished with a priest, a physician, a surgeon, an apothecary, and one prominent citizen whose duties were to consist in looking after the respectable poor. Then a large building in one of the suburbs was fitted up with kitchen, refectory, workshops, and machines suitable to the wants of the various trades. Over these were put master carpenters, smiths, turners, spinners, dyers, and so on, who were furnished with the necessary raw material for carrying on their different vocations. These were the teachers in the institution, which was called the Military School, and had for its object the reclaiming of the lowest orders to respectable modes of life. Besides the workshops, the building was fitted up as attractively as possible, and was made thoroughly neat and comfortable.

As soon as the arrangements were completed, the work of reformation was begun. New Year's Day was the great annual holiday of the beggars, who paraded the streets from morning till night, demanding alms in the most offensive manner, and making the thoroughfares almost impassable for the respectable classes.

On the morning of this festival Thompson had soldiers stationed all over the city, and he, with the civil authorities, started out on the bold venture of capturing every beggar in the streets of Munich. They had hardly reached the street when a beggar approached Thompson and extended his hand for alms; the decisive moment had come, and with a firm but gentle denial, Thompson laid his hand on the man's shoulder and declared him under arrest. His example was immediately followed by his associates, and the raid was as thorough as unexpected. Every vagabond in the streets was carried to the town-hall, and his name and residence taken, and orders given for him to appear next day at the Military School.

The beggars were astounded, but showed a better spirit than had been hoped for; the plan succeeded beyond the most sanguine expectations of its originator, and within a week twenty-six hundred beggars had presented themselves at the work-house and had started on a career of useful labor. Nothing can better illustrate the esteem which their benefactor was held in than the fact that, some time afterward, when these reclaimed outcasts learned of the critical illness of Thompson, they assembled in large numbers and, forming in a procession of hundreds, marched to the cathedral and offered prayers for his recovery.

A year after the organization of the Military School, Thompson was made a Count of the Holy Roman Empire, in token of the inestimable services he had rendered to Bavaria, he took the name of Rumford, from the little village in Massachusetts where he said that fortune first smiled upon him.

Count Rumford was constantly employed with some scheme to alleviate the condition of mankind, and Bavaria, under his guidance, was transformed as if by magic from a state of disorder and shiftlessness to prosperity and peace. In the world of science Count Rumford occupies a distinguished position. He made many valuable contributions to physics, but is chiefly known by his discoveries in heat.

Various theories had been held as to the origin and nature of heat, and the ancients had many curious idea in regard to this subject.

Up to the end of the eighteenth century the most generally accepted theory of heat was that it was a kind of subtle fluid which could enter the pores of bodies, and then be squeezed out again by compression. This fluid was called caloric, and was supposed—by its capability of combining with certain substances—to explain by its actions all the phenomena of heat.

Count Rumford, in opposition to this theory, asserted that heat was a form of motion, and that all its phenomena could be accounted for on this supposition alone.

This belief, like many other scientific creeds, was partly arrived at by accident. While watching one day the boring of a large brass cannon in the arsenal, he was struck by the great quantity of heat that was produced by the pressure of the boring bar against the brass. He immediately began some simple experiments with the filings to see how the heat might be accounted for, and the results led him to the conjecture that the thing known as heat was really a form of motion.

He made a test-experiment in the presence of some of his friends, causing a brass cylinder to be placed inside a wooden machine which contained a quantity of water, and then having the cylinder revolve against a steel borer. At the end of two hours the spectators were to see the water boil, although there was no fire near.

It had been known from the earliest times that friction would produce heat; but it was also generally supposed that the friction brought out the caloric that was latent or hidden in the bodies that were rubbed together. Rumford claimed, on the contrary, that if this were so there would be a limit to the amount of heat that could be obtained by the friction of two bodies, just as it is impossible to squeeze more than a certain amount of water out of a sponge; and as he had shown by experiment that there was no limit to the amount of heat that could be obtained by friction, he concluded that heat was not a substance which bodies contain as a sponge holds water, but that it was itself simply a form of motion. According to this view a hot body differs from a cold one in that its particles are in more vigorous motion.

This is called the dynamic theory of heat, and it is this contribution to scientific discovery that has connected Count Rumford with other great physicists.