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HISTORY OF THE TOWN OF MEDFORD, Middlesex County, Massachusetts, FROM ITS FIRST SETTLEMENT, IN 1630, TO THE PRESENT TIME, 1855. (ed. Charles Brooks), Chapter 1: (search)
undantly. Around its trunk the woodpeckers had drilled as many as five or six circles of holes, not larger than a pea; and, from this most visible peculiarity, the apples were called Woodpecker apples. By degrees their name was shortened to Peckers; and, during my youth, they were seldom called by any other name. How they came by their present appellative is this. Young Baldwin, of Woburn, afterwards a colonel, and father of Loami, was an intimate friend of young Thompson (afterwards Count Rumford); and, as lovers of science, they asked permission of Professor Winthrop to attend his course of lectures in natural philosophy, at Harvard College. Twice each week, these two thirsty and ambitious students walked from their homes in Woburn to bring back with them from Cambridge the teachings of the learned professor. One day, as they were passing by the Woodpecker tree, they stopped to contemplate the tempting red cheeks on those loaded boughs; and the result of such contemplations wa
Knight's Mechanical Encyclopedia (ed. Knight), A. (search)
rious proportions and relative qualities as to melting-point and gravity are collected from a multitude of sources, the best attainable. The authorities, however, differ somewhat widely, and this can only be accounted for from the fact that so few metals can be obtained pure. The differences in the metals obtained from different localities are often unsuspected, and are fully proven in the variable statements of the cohesion in the tables compiled by Muschenbroek, Tredgold, Barlow, Brown, Rumford, Rennie, Telford, Bramah, and others. The difficulty that has thus arisen has caused variable statements in the formulas for bell and ordnance casting, and has very considerably affected the exactness of statement in all the alloys, especially the more fusible ones, where the various combinations of lead, tin, and bismuth give such variable results. It appears to be scarcely possible to give any sufficiently general rules, by which the properties of alloys may be safely inferred from
Knight's Mechanical Encyclopedia (ed. Knight), C. (search)
hich the infusion passes from the infusion-vessel through a strainer into a reservoir. This is effected by simple filtration, by pressure of steam, or by producing a partial vacuum. Rumford's percolator. The percolator was invented by Count Rumford. The ground coffee is pressed between perforated diaphragms, so as by compactness to prevent the water from filtering through too quickly. 2. Coffee-pots having arrangements for condensing the steam and the essential oil, — which constitsh fireplaces. In some of the Louvre fireplaces the jambs have an angle of about 45° These were probably erected about 1750, by Gabriel, under the orders of M. de Mavigny. Gauger had previously (1715) given to the moving a parabolic curve. Count Rumford invented or adopted the inclined coving, having an angle of 135° with the fire-back, to radiate heat into the room. Cow. 1. (Mining.) A wooden wedge to jam against the barrel of a gin or crab, to keep it from revolving. (Prov. Eng.） <
Knight's Mechanical Encyclopedia (ed. Knight), F. (search)
contact with the back wall. The jambs are iron plates, solid backed. The channel a conducts the external air into the caliducts, which form a fire-back, and the warmed air escapes into the room at z. He also introduced the parabolic sides. Rumford contracted the fire-chamber and throat, and inclined the jambs. See coving. In 1745, Dr. Benjamin Franklin introduced a fireplace which he named the Pennsylvanian, in which Prince Rupert's descending flue was combined with Polignac's caliducts. This is shown at F. (Fig. 1997.) Count Rumford's improvements consisted mainly in the contraction of the chimney at the throat, the rounding of the breast-work, and the flaring of the covings, as illustrated in the accompanying plan and section G H. He preferred an angle of 45° for the covings. Arnott also made himself a name in this line. I J are a vertical section and plan showing an English tubular fireplace designed to warm a current of pure air derived from the outside, and
Knight's Mechanical Encyclopedia (ed. Knight), L. (search)
hile fresh charges are added at the top. It is charged with alternate layers of coal and limestone, in the proportion of one coal to four limestone, and is allowed to cool but once a year, for inspection and repairs. A kiln was invented by Count Rumford, having for its principal objects to consume the smoke, to bring a large surface of flame and hot vapor in contact with the limestone, to keep the latter separate from the fuel, and to allow the process to be continuous. It consists of a tece of emery-paper. These were superseded by mixtures containing phosphorus. See lighting-devices. Lu-cim′e-ter. An instrument for measuring the intensity of light. A photometer. Various photometers have been invented by Huyghens, Rumford, Celsius, Bouguer, Priestley, Ritchie, Arago, and others, which are described under that head. See photometer. Celsius called his device a lucimeter, and the name has since been adopted by Deslaurier in his modification of Bouguer's apparat
Knight's Mechanical Encyclopedia (ed. Knight), P. (search)
the boiling water is filtered through the ground coffee. The coffee-percolator was invented by Benjamin Thompson, Count Rumford. It consists of an upper cylindrical vessel with a perforated bottom, in which the ground coffee is placed and coverat the star was 27,664 times more distant than the sun; a conclusion from arbitrary premises. 2. One photometer of Count Rumford consisted of a number of pieces of dimmed glass, which were placed in succession in front of the light until the lighest distance from the eye, on which small circles painted on paper were distinctly visible in different lights. 4. Count Rumford, Priestley, Bouguer, and Lambert all gave their attention to this subject and elicited the following principle: — wo is ascertained. — Clegg. 5. The form of photometer founded upon the comparison of shadows has been ascribed to Count Rumford and to Dr. Priestley. The latter describes it as follows: — When two lights of varying intensity shine upon the s<
Knight's Mechanical Encyclopedia (ed. Knight), R. (search)
r apexes, where a portion of each is removed. At this central position, which is approximately at the foci of the reflectors, is a lamp c, whose beams are thus thrown in both directions in nearly horizontal beams of limited lateral divergence. 2. A short name for the reflecting-telescope (which see). 3. The reflector has also been extensively used for radiating the heat from an open fire into an apartment. Gas-light reflector. Street-car lamp-reflectors. Dr. Franklin and Count Rumford appear to have been the first who put forward intelligent ideas on this subject. As early as 1795, a patent was taken out in England for a removable reflector, and in 1805, polished metallic reflectors were placed on each side of the fireplace, to be turned at any angle to reflect the heat of the fireplace into the room. In 1816, the fire-grate was inclosed in a hollow metallic globe opening in front of the grate. In 1852, the hearth, cheeks, and faces of the grate were made of poli
Knight's Mechanical Encyclopedia (ed. Knight), T. (search)
. These are contained in a copper case a, having covers at each end, which may be removed to expose that part to heat. The terminals of the pile are connected by metallic rods b b′, with wires leading to a galvanometer c. When a beam of radiant heat strikes the pile, an electric current is produced, the amount of which is determined by the galvanometer. Thermo-multiplier. Ther′mo-scope. An instrument for indicating relative differences of temperature. The term was applied by Count Rumford to an instrument invented by him, and similar in principle to the differential thermometer of Professor Leslie. See differential thermometer. See also Fig. 6360. Any instrument which shows variations of temperature, whether or not it indicates the actual differences, is sometimes called by this name, including the thermometer. Such were those of Galileo, who in 1593 constructed thermoscopes, which were dependent concurrently on changes of temperature and on variations in the press
Knight's Mechanical Encyclopedia (ed. Knight), U. (search)
horse-power: 33,000 pounds raised 1 foot high per minute. The unit of atomic weights: hydrogen, 1. The unit of heat, or thermal unit, employed in Great Britain, is the quantity of heat which corresponds to 1 degree of Fahrenheit's scale in the temperature of 1 pound of pure liquid water, at about 39° Fah. The thermal unit of France is the quantity of heat which corresponds to an interval of 1° Centigrade in the temperature of 1 kilogramme of pure water at about 3.94° Centigrade. Rumford, in 1798, endeavored to ascertain the number expressing the precise relation between the functions of force and heat, known as the mechanical equivalent of heat. He used a solid plunger rotating against the bottom of an iron cylinder submerged in a box of water. Mayer and Joule farthered the experiment, the latter using paddle-wheels rotated in oil, mercury, or water by the force of a descending weight. The conclusions were, that the descent of 772 pounds 1 foot would raise the temperat
Knight's Mechanical Encyclopedia (ed. Knight), W. (search)
ick is treated with alum and gum, to preserve it from combustion. Le Count, October 30, 1866. Cotton threads run longitudinally through the wick, to increase its conducting power. Hoard, November 20, 1866. The wick is made of paper pulp. Martine, March 5, 1867. The wick has a core of wood, twine, or some firm substance that will consume with the wick; the addition gives stiffness to the wick, and enables the teeth of the elevating wheel to operate upon it more effectively. Count Rumford invented the flat wick of soft cotton woven for the purpose, of the right width. Argand of Geneva invented the tubular wick and the lamp named after him, which was the first lamp requiring a wick of that character. The modification of the Argand, invented by Fresnel, for lighthouse purposes, has 4 concentric wicks, the outer one 3 1/4 inches in diameter. L'Ange invented the lamp-chimney, adding it to the tubular wick and central air-tube of Argand. The mosque of Cordova was l
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