double acting

1. Lit.: Acting or exerting power in two directions. 2. To increase or extend to twice the original size, live steam, which bears upon the faces alternately; extent, quality, or value. "This was only the value of the silver; there was besides a tenth part of that number of talents of gold, which, if gold was reckoned in a decuple proportion, will just double the sum."- Arbuthnot: Coins. 3. To give or return twice the quantity or amount. "Reward her even as she rewarded you, and double unto her double according to her works; in the cup which she hath filled fill to her double." -Rev. xviii. 6. 4. To be double or twice the amount, size, or as many; to exceed by an equal number, amount, C. As substantive: I. Ordinary Language: 1. Literally: (1) Twice the quantity, amount, value, or sum; twice as much. "In all the four great years of mortality above mentioned, I do not find that any week the plague increased to the double of the precedent week above five times."Graunt: Bills of Mortality. (2) A fold, a plait, a doubling. (3) A turn in running to escape pursuit. "And when thou hast on foot the purblind hare, Mark the poor wretch, to overshoot his troubles How he outruns the wind, and with what care He cranks and cro es with a you sand doubles ." Shakesp.: Venus and Adonis , 679-82. 2. Figuratively : *(1) A trick, an artifice, a shift, a scheme. "I would now rip up All their arch-villanies, and their doubles." Beaum. & Flet.: Woman's Prize , iii. 1. (2) Something exactly like another; a counterpart, a counterfeit, a duplicate, an exact copy. "He put in the Marquis' hand a double of the late proclamation from England."- Baillie : Letters , i. 174. *(3) Strong beer, beer of twice the ordinary strength, marked XX. II. Technically : 1. Eccles.: As many of the holy days of the Church are fixed to certain determinate days of the year, and the others, including all the Sun days, are continually subject to change in their days, it must nece arily follow that two holy days will occasionally come together on the same day of the year, and consequently that for such a day there will be two sets of le ons for morning and evening prayer, with two collects, epistles, and gospels. These days are technically called Doubles. Concurrent Holy-days, or Duplex Festivals. 2. Milit .: The quickest step or pace in marching. In the double the soldier takes 165 steps, of 33 inches each, in the minute. [DOUBLE-QUICK.] 3. Music : (1) An old term for a variation. In some of Handel's harpsichord le ons, the variations of a theme are marked Double 1, Double 2, . A variation on a dance tune is also called a Double. (2) The repetition of words in singing was also called the" Doubles or ingeminations thereof." (3) An artist who understudies a part in an opera or play, that is, who prepares a part on the chance of the accidental absence of the principal. (4) That which is an octave below the unison in pitch, i. e., double-ba , an instrument whose sounds are an octave below those of the violoncello; double-ba oon, an instrument similiarly sounding an octave below the ba oon; double diapason, an organ-stop of 16-feet pitch. (5) A turn. ( Stainer & Barrett.) 4. Print.: Several words, lines, or pa ages set up twice; among pre men, a sheet that is twice pulled and mackled. 5. Build.: The smallest size of roofing slates, measuring thirteen inches by six inches. or quantity. "Thus reinforced against the adverse fleet, Still doubling ours, brave Rupert leads the way; With the first blushes of the morn they meet, And bring night back upon the newborn day." Dryden: Annus Mirabilis , cxix. 5. To redouble, to repeat, to add to a preceding. "He saw proud Arcite and fierce Palamon In mortal battle doubling blow on blow; Like lightning flamed their fauchions to and fro." Dryden: Palamon and Arcite , ii. 242-44. 6. To make two of one. "His face seems twain, each several limb is doubled." Shakesp.: Venus and Adonis, 1,067. in contradistinction to single-acting, in which live steam is only admitted to one side of the piston, the weight of the pump-rod or the pre ure of the atmosphere giving the return motion. This form of engine was invented by Watt. The piston of the Newcomen atmospheric engine, on which Watt was improving, was raised by steam at a moderate pre ure, and depre ed by the pre ure of the atmosphere when the steam beneath the piston was condensed by a water-jet. Watt added the separate condenser, air-pump, and steam-jacket to the cylinder, and then sought for means for keeping the atmosphere from the inside of the cylinder when the piston was depre ed. He added the cylinder cover, adopted the stuffing-box invented by Sir Samuel Morland, and admitted steam above the piston to occupy the space formerly filled with air. The steam retreated as the piston rose, and was afterward utilized beneath the piston. Eventually the steam was regularly inducted above and below the piston alternately, in each case giving a positive pre ure: here we have the double-acting engine. Double - acting inclined plane : An inclined plane on which the loaded wagons, as they descend by their weight, pull up the empty wagons by means of a rope pa ing round a pulley or drum at the top of the inclined plane. Double - acting pump A pump which throws water at each stroke; contradistinguished from the ordinary lift-pump, in which the bucket only raises *7. To make a duplicate or copy of; to copy. "Some of the advertisement I have caused double." - water at the up-stroke. Baillie: Letters, i. 174. 8. To increase by adding something equally great or important. "With joy he will embrace you; for he's honorable, And, doubling that, most holy." Shakesp.: Cymbeline , iii. 4. 9. In the same sense as II. 2. II. Technically : 1. Milit .: To unite two ranks or files in one. 2. Naut .: To sail round or by; to pa round a headland. "We closed in with the Barnevelts, and running past Cape Deceit, with its stony peaks, about three o'clock doubled the weather-beaten Cape Horn." Darwin: Voyage round the World , ch. x., p. 211. B. Intransitive: I. Ordinary Language: 1. Literally: (1) To increase, extend, or become enlarged to twice the original size, amount, quantity, or value; to become twice as much or as great. "Tis observed in particular nations, that within the space of three hundred years, notwithstanding all casualties, the number of men double."-Burnet: Theory. (2) To enlarge a wager or stake to twice the previous sum or amount. "Throw Egypt's by, and offer in the stead, Offer the crown on Berenice's head; I am resolved to double till I win." Dryden: Tyrannic Love, iii. 1. (3) To turn or wind in running to escape pursuit. *2. Fig.: To use tricks or artifices; to scheme, to IMG:content-0401.png:[blocks in formation] double-action. Music : In a pianoforte movement, an arrangement of a jointed upright piece at the back end of the key, used to lift the hammer instead of the stiff wire or lifter of the single-action. The piece is called a hopper, and engages in a notch on the under side of the hammer to lift it, but, escaping or hopping therefrom, allows the hammer to fall away immediately from the string.