LOG 



436 



LON 



garithms are a series of numbers in arith- 

 metical progression, answering to another 

 series of numbers in geometrical progres- 

 sion ; or, more strictly, they are the indices 

 of the powers of a certain radix, which, 

 when involved by the power denoted by 

 the index, is equal to the given number. 

 Thus, if r* a, ry, = 6, r=, c, then is x 

 the logarithm of a, y of 6, z of c, and r is 

 the radix of the system, and may be any 

 number except 1. 



LOOARITH'MIC or LOGIST'IC CCRVE. In 

 geometry, a curve line, of which the ab- 

 scissie are proportional to the logarithms 

 of the corresponding ordinates. 



LOGARITH'MIC or LOGIST'IC SPIRAL. In 

 geometry, a spiral curve, such that the ra- 

 diants, or distances from the centre of 

 points in the curve, which make equal 

 angles with each other, are continual 

 proportions. 



LOG'GA.TS, kittle-pins. A game prohi- 

 bited by Stat. 33 Henry VIII. 



Looic, Lat. logica, from Ay;-/j, from 

 Kiyca, to speak. The art of thinking and 

 reasoning justly. 



LOOIST'IC SPIRAL. Logarithmic spiral. 

 A curve constructed thus: divide the 

 quadrant of a circle into any number of 

 equal parts in the points A, B, C, D, &c.. 



and from the radii CA.CB.CC.CD, &c., cut 

 off Ca, C6, Cc, C<i, &c., continually pro- 

 portional ; then the curve passing through 

 the points a, b, c, d, &c. will be the log- 

 arithmic spiral. The several areas are 

 as the logarithms of the ordinates. 



Loo'ooRAPHr, from Aoyo?, a word, and 

 yooQtii, to write. A mothod of printing, 

 in which a type represents a word, in- 

 stead of forming a letter. 



IIOGOMET'RIC, from Aoya?, ratio, and 

 W.ITO, measure, ratio of equivalents. 

 Wollaston's scale of chemical equivalents 

 has been termed a logometric scale, 



LOO'WOOD. The wood of the Heematoxy- 

 lon Campechianum, a native tree of cen- 

 tral America, but grown in Jamaica since 

 the beginning of the last century. It af- 

 fords a valuable tincture by decoction, 

 extensively used in dyeing and calico- 

 printing. 



Lo LICM. The Darnel-grot*. A genus. 

 Triandria Digynia. The L. pcrcnne. a 

 perennial, of which there are no less than 

 14 varieties, is the grass usually known 

 among farmers by the name of Rye-(jraiti. 

 The other species are annuals, and con- 

 sidered weeds. 



LOI/LA.RDS. A sect of early reformers in 

 England and Germany; followers of 

 Wickliffe. 



LOM'BARDS. The old name for bankers, 

 because the people of Lombardy first fol- 

 lowed that branch of trade. Hence also 

 the name Lombard Street, long famous for 

 its banking-house*. 



LO'MENT, Lat. lomentum. \. The meal 



ot beans. 2. Bean-meal bread. 3. 



The name of a pigment now. forgotten. 

 I. In botany, an elongated bivalve 

 pericarp, divided into cells by very small 

 partitions, never lateral like those of the 

 legume. 



LOMENTA'CEJJ. The name of the 33rd 

 natural order of plants in Linnreus' Frag- 

 ments, consisting of plants furnished with 

 loments, as the cassia. ceretonia, mimosa, 

 &c., and not papilionaceous ' corols. 

 Epithet Lomentaceous. 



LONDON CLAY. A bluish or blackish clay, 

 lying immediately over the plastic clay and 

 gand ; varying.from 1 to more than 500 feet 

 in thickness. " It belongs to the eocene 

 period, and abounds with fossil remains, 

 especially of testaceans, reptiles and fish. 

 It is the calcaire grassier of the French. 



LONO. A musical character, equal to 

 four ssmibreves. 



LOXGICOR'NES, from longiu, long, and 

 ornu, a horn. A family of coleopterous 

 insects in Cuvier's arrangement, so named 

 from the length of their antennae, which 

 are filiform or setaceous, and most com- 

 monly at least as long as the body. 



LOXQIPEN'XES, from longus, long, and 

 penna, a wing. A family of birds in 

 Cuvier's arrangement, including those 

 palmipedes of the high seas, which, from 

 their immense length of wing, are to be 

 met with in every latitude ; as the petrels, 

 puffins, albatross, gulls, noddies and 

 skimmers. 



LONGIROS'TRZS, from longus, long and 

 rontrum, a bill. A family of birds of the 

 order Grallatorice, Cuv., composed of a 

 multitude of waders, characterised by a 

 long, slender, and feeble bill, the use of 

 which is restricted to searching in the 

 mud for worms and insects ; as the ibis, 

 curlews, snipes, &c. 



LONOIS'SIMUS DORSI, a muscle of the 

 back, which assists others in keeping the 

 spine erect. 



LON'OITXTDE, Lat. longittido, from longus, 

 long; properly, length. The longitude of 

 a celestial body is its angular distance from 

 the vernal equinoctial point ; that is, if ft 

 great circle pass through a star perpea 



