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Confequently the fonorous rays will be reilefted parallel to 

 the axis of the tube. But Mr. Martin obferves, that this 

 parallel refleftion is by no means eflential to the magnifying 

 of found ; on the contrary, it prevents the infinite number 

 of refleftions and reciprocations of found, in which, accord- 

 ing to fir I. Newton, its augmentation principally confifts : 

 the augmentation of the impetus of the pulfes of air being 

 proportional to the number of repercuffions from the fides 

 of the tube, and therefore to its length, and to fuch a 

 figure as is mod produdtive of them. Hence he infers, 

 that the parabohc trumpet is the mofl unfit of any for this 

 purpofe. 



He obferves, that there is one thing more which contri- 

 butes to the augmentation of the agitations of air in the 

 tube ; v!x. the proportion which the leveral portions of air 

 bear to each other when divided by tranfverfe feftions, at 

 very fmall, but equal diftances, from one end of the tube 

 to the other. 



Thus, let thofe feveral divifions be made at the points 

 a, b, c, d, e, Sec. {fg. 8.) in which let the right lines 

 ah, bl, cm, dn, &c. be taken in geometrical proportion. 

 Then will the portions of air contained between B and a, 

 a and b, b and c, c and d, &c. be very nearly in tlie fame 

 proportion, as being in the fame ratio with their bafes, when 

 the points of divifion are indefinitely near together. But it 

 is known, that when any quantity of motion is communi- 

 cated to a feries of elaftic bodies, it will receive the greateft 

 augmentation when thofe bodies are in geometrical propor- 

 tion. Therefore, fince the force of the voice is imprelfed 

 upon, and gradually propagated through a feries of elaftic 

 portions of air in a geometrical ratio to each other, it eafily 

 receives the greateft augmentation poffible. 



And fince by conftruftion ^a = ab=:.bc:=cd, &c. and 

 <i i : bl :i bl : cm:: cm : d n, &c. the points k, I, m, n, o, p, 

 q, r, s. A, will form the logarithmic or logiftic curve : 

 whence Mr. Martin concludes, that a trumpet formed by 

 the revolution of this curve about its axis, will augment 

 the found in a greater degree than any other figured tube 

 whatever. 



CafTegrain alfo is of opinion, that an hyperbola, having 

 the axis of the tube for an afymptote, is the beft figure for 

 this inftrument. Mufchenb. Int. ad Phil. Nat. torn. ii. 

 p. 296, 4to. Martin's Phil. Brit. vol. ii. p. 248, 3d edit. 



For other conftrudlions of fpeaking trumpets by Mr. 

 Conyers, fee Phil. Tranf. N° 141. for 1678. 



Trumpets, Feajl of, in Ecclepajllcal H'ljlory, one of the 

 menftrual feafts among the Jews, kept with greater fo- 

 lemnity than the reft, on the firll day of the month Tifri. 

 (Numb. xxix. 1 — 6. Levit. xxiii. 24, 25.) The day of this 

 feaft was the new-year's day of the Jews, in which the 

 people were folemnly called to rejoice in a grateful remem- 

 brance of God's benefits to them through the laft year, 

 which might be intended by blowing the trumpets, as well 

 as to implore his bleffing upon them for the enfuing year, 

 which was partly the intention of the facrifices offered on 

 this day. 



The modern Jews have a notion, which they derive from 

 the Mifchna, that on this day God judges all mankind ; and 

 therefore, according to Bafnage, their zealots fpend, fome 

 a whole month, others four days, and efpecially the eve 

 of this feaft, in confeffing their fins, beating their breafts, 

 and fome in lalhing their bare backs, by way of penance, 

 in order to procure a favourable judgment on this decifive 

 day. 



Trumpet- Fi/J, Scolopax, in Ichthyology, a fifh called alfo 

 the bellows-jijh. In the Linnsean fyftem it is a fpecies of 



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the centrifcus; but in the Artedian, a fpecies of baliflet. 

 Phny calls \t ferra. See Centkiscus Scolopax. 



TiiUMPET-Flower, in Botaaj. See BiuNO.NiA and Lo- 



MICEKA. 



Tv-UMVET-Honeyfucile. See Lonicera. 

 'TRVMPii,T. Shell, or Whelk, Buccinum, in Natural Hipry, 

 the name of a large genus of fhells, the charafters of which 

 are thefe : they are univalvt /hells of the form of a trumpet, 

 according to old pifiures, with a wide belly, and a large, 

 broad, and elongated mouth ; they have a diftinft and regu- 

 lar tail, ufually long, though fometimes ftiort ; they have a 

 crooked beak, and the clavicle is often elevated, though 

 fometimes depreffed and contabulated. In the Linnaa.T 

 fyilem, the charafters of this genus are, that its animal is a 

 Aug, the Ihell univalve, fpiraf, and gibbous, the aperture 

 oval, ending in a fhort canal or gutter. Linnseus enume- 

 rates fifty-one fpecies. See Conchology. 



The family of the buccina, when examined ever fo 

 ftriaiy, is very large ; but according to the general cuftom 

 of authors, of confounding together feveral genera under 

 the name, it is ufually made to appear much larger than it 

 really is. Lifter has made it comprehend a vaft number of 

 fliells, by confounding it with the families of the murex and 

 purpura. 



It is not indeed peculiar to this author, to have con- 

 founded thefe genera : thofe who went before him have done 

 the fame ; and Phny has comprifed the buccinum, murex, 

 and purpura, under the general name ceryx. 



To avoid the general confufion, which arifes from not 

 diftinguilhing the families of the buccinum, murex, pur- 

 pura, and vis, or fcrew-fliell, it will be proper to obferve, 

 that there are regular charafters, which diftinguilh them all, 

 one from another : the charafters arc thefe : the buccinum 

 differs from the purpura, in that it has a very long mouth 

 of an oval figure, and has an elevated head ; whereas the 

 purpura has a round mouth, and a head fomcwhat flatted ; 

 the tail of the purpura is alfo ufually furrowed, and is 

 ihorter than that of the buccinums. 



The buccinum differs alfo from the murex in having a 

 longer tail, by the fmoothnefs and variety of colours of its 

 coat, and by having a larger mouth lefs furnifhed with 

 teeth ; the murex having a fmaller and longer-fliaped 

 mouth, its furface covered with points or fpircs, and feve- 

 ral teeth. 



It is eafier to diftingui/h the buccinum from the fcrew- 

 /hell, as this is always more long and flender than the 

 buccinum ; it has alfo a flat mouth, and has rarely any 

 tail. 



The moft fingular fpecies of the buccinum clafs, is one 

 that has its mouth turned the contrary way to all other 

 (hells : this lias been thence called by authors, the unique 

 and the fans pareille. 



The buccina generate in the warm months, and fome 

 fpecies of them are fecn very frequently remaining in pairs 

 together, upon the rocks deferted by the tide on that oc- 

 cafion. Thefe have been thence fuppofed to be of a dif- 

 ferent genus, and have been called buccina lilloralia ; they 

 are ufually found in copulation early in the morning. Rum- 

 phius de Teft. AKirovand. de Teft. lib. iii. cap. 231. 

 Lifter, Hift. Animal. Angl. p. 158. 



The fpecies of the buccina being very numerous, they 

 are arranged under feveral diftinft heads, according to cer- 

 tain obvious diftinftions, and are as follow : of the buccina, 

 with long diilinft tails and oblong mouths, there arc thirteen 

 fpecies ; of thofe with a Ihort tail and a wide mouth, we 

 have twelve fpecies ; of thofe with long ercd clavicles, there 



arc 



