TRU 
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831; 
large eiul of the tube, and greatly multiplied 
pud condensed by the tremulous motion of 
the parts of the tube, and air agitated by 
them, are conveyed to the ear by the small 
lend, and strike it with an impetus as much 
greater than they would have done without 
it, as the area of the small end at B is less 
than the area of the larger end AC. From 
kvhat has been said, it is evident the effect of 
[the tube in magnifying sound, either for 
Speaking or hearing, depends chiefly upon 
[the length of the tube. But yet some advan- 
tage may be derived from the particular 
shape. Some very eminent philosophers 
have proposed the figure which is made by 
the revolution of a parabola about its axis, as 
the best of any, where the mouth-piece of the 
parabola, and, consequently, the sonorous 
rays will be reflected parallel to the axis of 
the tube. But this parallel reflection seems 
no way essential to the magnifying of sound ; 
on the contrary, it appears rather to hinder 
such an effect, by preventing the infinite 
number of reflections and reciprocations of 
{sound ; in which, according to sir Isaac 
(Newton, its augmentation principally consists. 
For all reciprocal motion, in every return, is 
augmented by its generating cause, which is 
here the tremulous motions of the parts of 
the tube. In every repercussion, therefore, 
from the sides of the tube, the agitations and 
pulses of confined air must necessarily be in- 
creased ; and consequently this augmentation 
of the impetus of the pulses must be propor- 
tional to the number of such repercussions ; 
and therefore, to the Length of the tube, and 
to such a figure as is most productive of them. 
"Whence it appears that the parabolic trumpet 
is of all the most unfit for tiiis purpose, in- 
stead of being th best. 
But there is one thing more which contri- 
butes to the augmenting of these agitations of 
air in the tube, and that is the proportion 
, which the several portions of air bear to each 
other, when divided by transverse sections, 
I at very small, but equal distances, from one 
j end of the tube to the other. Thus, let 
those several divisions be made at the points 
a, b, c, cl, e, See. which let the right lines ak, 
bl, cm, da, Sec. be taken in geometrical pro- 
portion. Then will the portions of air con- 
tained between B and a, a and b, b and cc, cc 
and d, Sec. be very nearly in the same pro- 
portion, as being in the same ratio with their 
bases, when the points of division are indefi- 
nitely near together. 
But when any quantity of motion is com- 
; municated to a series of elastic bodies, it will 
receive the greatest augmentation when those 
bodies are in geometrical proportion. There- 
fpre, since the force of the voice is impressed 
upon, and gradually propagated through, a 
[ series of elastic portions of air in a geome- 
trical ratio to each other, it shall receive the 
greatest augmentation possible. 
Now, since by construction it is B a=ab= 
be = cd, Sec. and also ak : bl:: bl : cm : : cm : 
I dn, and so on ; therefore, the points k, l, m, 
11, o, p y k, r, s, as will, in this case, form that 
curve line which is called the logarithmic 
curve ; consequently a trumpet, formed by 
the revolution of this curve about its axis, 
will augment the sound in a greater degree 
than any other figured tube whatever. 
Trumpet, listening or hearing, is an in- 
strument invented by Joseph Land ini, to as- 
sist the hearing of persons dull of that faculty. 
T 11 U 
or to assist us to hear persons who speak at a 
great distance. 
Instruments of this kind are formed of 
tubes, with a wide mouth, and terminating 
in a small canal, which is applied to the ear. 
The form of these instruments evidently 
shews how they conduce to assist the hearing, 
for the greater quantity of the weak and lan- 
guid pulses of the air being received and col- 
lected by the large end of the tube, are re- 
llected to the small end, where they are col- 
lected and condensed ; thence entering the 
ear in this condensed state, they strike the 
tympanum with a greater force than they 
could naturally have done from the ear alone. 
Hence it appears that a speaking-trumpet 
may be applied to the purpose of a l.earing- 
trumpet, by turning the wide end towards 
the sound, and the narrow end to the ear. 
Trumpet-feower. See Bignonia. 
Trumfet-shell, the English name of 
the buocinum of authors. SeeBucciNUM. 
TRUNCATED, in general, is an appel- 
lation given to such things as have, or seem to 
have, their points cut off: thus we say, a 
truncated cone, pyramid, leaf, Sec. 
In entomology it means when the elytra 
(or upper wings) are shorter than the abdo- 
men, and terminated by a transverse line. 
TRUNNIONS, or Trunions of a piece 
of ordnance, are those knobs or bunches of 
the gun’s metal, which bear her up on the 
cheeks of the carriage : and hence the trun- 
nion-ring is the ring about a cannon, next be- 
fore the trunnions. 
TRUSS OF FLOWERS, is used by flo- 
rists to signify many flowers growing together 
on the head of a stalk, as in the cowslip, au- 
ricula, &c. 
Truss is also used for a sort of bandage or 
ligature made of steel, or the like matter, 
wherewith to keep up the parts, in those who 
have hernias or ruptures. See Surgery. 
Trusses, in a ship, are ropes made fast to 
the parrels of a yard, either to bind the yard 
to the mast when the ship rolls, or to luile 
down (he yards in a storm, Sec. 
TRUST, is a right to receive profits of 
land, and to dispose of the land in equity. 
Ami one holding the possession and disposing 
of it at his will and pleasure, are signs of trust. 
Chan. Rep. 52. 
A trust is but a new name given to an use, 
and invented to evade the statute of uses. 21 
Vin. 493. 
Ik' hat is a declaration of trust, and when 
a trust shall he raised. By stat. 29 C. II. c. 
3; all declaration or creation of trust shall be 
manifested by some writing signed by the 
party, or by his last will in writing, or else 
shall be void. And by sect. 9 of the same 
act, assignments of trust shall be in writing, 
signed by the party assigning the same, or by 
his last will, or else shall be of no effect. 
What shall be deemed V trust by implica- 
tion. By 29 Car. II. all declarations of trusts 
were to be made in writing ; but in the said 
act there is a saving with regard to trusts re- 
sulting by implication of law, which are left 
on the footing whereon they stood before the 
act ; now a bare declaration by parole before 
the act, would prevent any resulting trust. 
2 Yern. 294. 
If a man purchases lands in another’s name, 
and pays the money, it will be a trust for him 
th it paid the money, though no deed is made. 
TRUSTEE, one who has an estate, or 
money, put or trusted in his hands, for the 
use of another. Where two or more persons - 
are appointed trustees, if one of (hem only 
receives all or the greatest part of the profits of 
the lands. Sec. and is in arrear, and unable to' 
satisfy the person to whom he is seised in 
trust, the other, in that case, shall not be 
answerable for more than comes to his hands. 
TUBE, in general, pipe, conduit, or canal ; 
a cylinder, hollow withinside, either of lead, 
iron, wood, glass, or other matter, for the air, 
or some other fluid, to have a free passage or 
conveyance through. 
Small silver or leaden tubes are frequently 
used by surgeons to draw off" blood, matter, 
or water, from the different parts of the body.. 
They are made of various sizes and shapes. 
’Tube, in astronomy, is sometimes used for 
a telescope, or, more properly, for that part 
into which the lenses are fitted, and by which 
they are directed and used. See Optics. 
TUBIPORA, a genus of zoophyta The 
generic character is, animal a nereis ; coral 
consisting of erect, hollow, cylindrical, paral- 
lel aggregate tubes. There’are ten species i 
the musica inhabits the American and Indian 
seas, is fixed to rocks and other corals ; bright 
scarlet, consisting of an assortment of upright 
parallel tubes, rising over each other bv 
stages, like cells of an honeycomb, divided 
by transverse partitions. The Indians use it 
incases of strangury, and wounds inflicted by 
venomous animals. 
TUBULARIA, a genus of zoophyta: stem 
tubular, simple or branched, fixed by the, 
base: animal proceeding from the end of the 
tube, and having its head crested with tenta- 
cula. 'There are 26 species ; the magnitica 
' inhabits the West Indies, adhering to rocks, 
and is the most splendid genus of them all : 
it has the power of withdrawing its tcntacula 
within the tube, and the tube w ithin the rock 
on which it resides. 
TUFAS, beds of lime deposited on vege- 
tables, which by their destruction give great, 
lightness and porousness to the mass. 
'FUG, in military affairs, Fr. A Turkish 
term for tail ; a sort of standard, called so by 
the Turks. It consists of a horse’s tail, which 
is fixed to a long pole or half-pike, by means 
of a gold button. The origin of this standard 
is curious, it is said, that the Christians hav- 
ing given battle to the Turks, the latter were 
broken, and in the midst of their confusion 
lost their grand standard. 'The Turkish ge- 
neral, being extremely agitated at the untow- 
ard circumstances which happened, most 
especially by the loss of the great standard, 
cut off a horse’s tail with his sabre, fixed it to 
a half-pike, and holding it in his hand, rode 
furiously towards the fugitives, and exclaim- 
ed, * Here is the great standard ; let those 
who love me, follow into action.’ This pro- 
duced the desired effect. 'The Turks rallied 
with redoubled courage, rushed into the 
thickest of the enemy, and not only sained 
the victory, but recovered their standard. 
Other writers assert, that six thousand 'Turks 
having been taken prisoners during a general 
engagement, contrived to escape from their 
guard or escort, and afterwards fought so 
gallantly, that they regained another battle ; 
that in order to recognize one another, (hey 
cut off a horse’s tail, w hich they carried as a 
standard; that when they joined the Otto-- 
