What Is "one-horse Power?"

The use of the term "hor3e power" is very conimon, yet few, excapt good meohanics end engineera, attaeh a defiuite meauiüg to it, but regard it as indicating loosaly, about tho power wliich one liorso would üsert. It is, however, when used in tho sonsa under consideraron, as donnite as possibla, and means the potver required to lift 33,000 pounds avoirdupoia one foot high ia one minute. A horsc hitched to the end of a ropo over a pully one foot in diameter placo over a doep well, traveling at the rate of abont 2h miles per hour, or 220 feet por minute, will draw up 150 pounds the saine distanoe he travels. The force thus exerted is called in inechanics, a "horse power," it being au approximation to the average amount of continuous power it is fair to demand of a stroog horse. If we multiply the weight raised (150 pounds) by the num bor of feet it wa3 moved per minute, (220) the product vvill ba the number of pounda wlrieh the same power would raise only ono foot high in the same length of time, (33,000 pounds.) The dyaatnorneter ia an instrument made for measuring power, particularly that exerted in drawing. Thos3 used for testing the draffc of agrioultural implements are simply vory stroug spring balances, or spring stoelyards, graduated to indicate the powor requir ed to raise any weight, within resonable limit, at the rato of 2L miles per hour. When wo apply" the dynamoraeter, in ascertaining the draft of machines, if the index indícales 150 pounds, it is shoton that the horse ia required to draw just as hard as he would do, ifraisiog 150 pounds out of a well with a rope over a pulley one foot in diameter, at the rate of 2.} miles per hour, and so for other weights. The veloaity at which a team, moves is to bo considered, aa weil as the t to bo raised, or the load to be drtvwu. Ifa horse travels faster than 2J miles per hour, while raisiug 150 pouudsoutofa wol!, he exerts moro than ono horso power. If ho walks slower thaa this, ho does not exert a force equal to one-horse power. In ascertaiuiug the draught of a plow, or retipor and mower, by driving faoter than 2J per hour, tho dynamometer would indicate more than tho correot draught; and by driving slower, the draught woutd appear to be leas than it rüally is. ín testing the draught oL machines a tecia ahould alvvays move nt tho rate of 2} miles per hour, or 220 foot per minute, whiob is the universallally accepted rato ,with referenco to whioh dynamomotera are graduated, ■and an easy one to whioh to approximate in driving with almost any kind of team. Many peoplo have suppose that 300 ' pounds- two-horse power - ropresented the same force that a team would exert, when dragging 300 pouuds along on the ground. A horae can haul G0O pounds on the hard ground, with ease; bul ho could not draw hard enough on the dynamorneter to mark more than ■i.,0 to 300 pouuds, except for a fow minutes. Tho power of a man is ostiuinted at one-fiftli of a horse powor i American Agriculturisl. A man 's roputation often depapda on the placa whero ho falla, asleep. íf in a drinking saloon, ho is thought a drunkard ; f iu tl churoh he ia regarde as a KoJel of pieiy. I