Friction-cones, 
and f>, cones ; c, fork. 
fractionally 
frictipnally (frik'shon-al-i), adv. As regards 
friction. 
friction-balls (frik'shon-balz), n. pi. Balls 
placed under a heavy object to reduce the fric- 
tion while that object is moving horizontally. 
Some forms of swing-bridges have such balls 
placed under them. 
friction-brake (frik'shon-brak), . 1. A brake 
acting by friction on some part, as of a moving 
vehicle. 2. A form of dynamometer invented 
by Prony. 3. An apparatus for testing the 
lubricating properties of oils. 
friction-breccia (ft-ik'shon-broob/ia), n. In 
geol., angular or sometimes imperfectly round- 
ed fragments of rock filling more or less com- 
pletely the cavity left between the sides or 
walls of a fault or fissure. This material may have 
been torn from the walls as one of the results of the vio- 
lent motion to which the rock was subjected at the time 
the fissure originated, or it may have fallen in from above 
after the cavity had been formed. Mineral veins are not 
infrequently made up in considerable part of brecciated 
material derived from the rubbing together and crushing 
of the adjacent rock. Large masses of rock thus occur- 
ring in a vein are called horses. Friction-breccia is also 
sometimes called fault-rock. See vein and horse. 
friction-card (frik'shon-kard), n. The diagram 
produced by the indicator of a steam-engine 
when it is applied to exhibit graphically the 
power of an engine working without load, 
friction-clutch (frik'shon-kluch), n. Inmach., 
a form of friction-coupling. 
friction-cones (frik'shon-konz), n.pl. In mach. , 
a form of friction-coupling consisting of two 
cones, one of 
which is fitted into 
the other and com- 
municates its mo- 
tion to it by means 
of the friction be- 
tween the two sur- 
faces. See fric- 
tion-coupling. 
friction - coupling 
(frik'shon-kup'"- 
ling), n. In mach., 
a device for conveying motion from one line of 
shafting to another by the frictional contact of 
cones, expanding toggles, and clutches of vari- 
ous forms. In all these appliances a sleeve sliding on 
one of the shafts and turning with it may be advanced 
or drawn back at will to bring 
the parts into action. In the 
friction-cone coupling a conical 
disk is pushed at will into a hol- 
low cone, the two surfaces fit- 
ting closely together, and either, 
when in motion, imparting it* 
motion to the other by friction. 
In other friction-couplings the 
sliding sleeve causes a pair of 
toggles to expand against the in- 
ner rim of an idle pulley, and 
by their contact to impart to it 
th(' 
heir motion ; or the movement 
of sliding levers over a cone 
causes two pulleys to he drawn 
together into frictional contact, 
or causes two disks to press one 
Friction-coupling. against the other. In all these 
couplings the object sought is 
to connect parts of a line of shafting by frictional con- 
tact instead of direct contact, as in a geared wheel, and 
to obtain the same advantages in a coupling that are 
found in friction-gearing. 
friction-gear (frik'shon-ger), . Same as fric- 
tion-gearing. 
friction-gearing (frik'shon-ger'ing), n. A 
method or system of imparting the motion of 
one wheel or pulley to another by simple con- 
tact. The advantages of 
this kind of gearing are 
threefold : it enables the 
parts of a machine to be 
thrown quickly into or 
out of play ; it gives a 
variable speed or power ; 
and it prevents the injury 
caused by a breakage or 
stoppage from extending 
from one part of the 
mechanism to another or 
from the machine to the 
motor. The most simple 
form of friction -gearing is 
a pair of wheels with thin 
faces, which may be cov- 
ered with leather, a fabric, or other elastic material, in 
more or less close contact. In some such wheels the faces 
are grooved, or the wheels are cone-shaped and placed at a 
right angle and with grooves cut on the faces. In others 
a collar on a shaft may carry pivoted arms which if turned 
one way press against the inner face of a wheel, and if 
turned the other way fall back out of contact and cease 
to impart their motion. Irj other forma one wheel revolves 
within another, contact being assured by means of springs. 
If the resistance overcomes the springs the contact is de- 
stroyed and motion is no longer imparted. Variable speed 
and reversal of direction are also secured by causing a 
friction-wheel placed at right angles with adisk and against 
Friction-gearing, grooved. 
2378 
it to move from the rim toward the center or past the cen- 
ter of the disk, as in the feed-motion of some forms of 
gani;-saws. 
frictionless (frik'shon-les), a. [< friction + 
-less.] Without friction. 
Were water absolutely frictionless, an incline, however 
small, would be sufficient to produce a surface-flow from 
tlie equator to the poles. 
J. Croll, Climate and Time, p. 220. 
The joints and bearings of all the levers are made fric- 
tionless by using flexible steel connecting plates instead of 
knife-edges. Encyc. Brit., XXII. 597. 
friction-match (frik'shon-mach), n. A match 
tipped with a compound which ignites by fric- 
tion : the usual form of match in domestic use. 
The first chemical matches were invented in Paris in 1805 ; 
and soon after 1827, when the composition of friction- 
matches was much improved by an English chemist, they 
came into general use, superseding the various applica- 
tions of the flint and steel which had until then been re- 
lied on. 
friction-plate (frik'shon-plat), n. 1. A metal 
plate attached to any surface to prevent abra- 
sion or resist friction. 2. A plate used in con- 
nection with a clamp to check the recoil of a 
gun-carriage. 
friction-powder (frik'shon-pou' l 'der), n. A com- 
position of chlorate of potash and antimony, 
which readily ignites by friction. 
friction-primer (frik'shon-pri'mer), n. A fric- 
tion-tube. [U. S.] 
friction-SOUnd (frik'shon-sound), n. In pathol., 
the sound perceived on auscultation of serous 
surfaces which rub together when through dis- 
ease they are roughened or not well lubricated. 
friction-tight (frik'shon-tit), a. In mach., fit- 
ting so tightly or closely that a desired effect 
of friction is produced. Noting (a) A mechanical 
fit, joint, or union between the surfaces of two assembled 
parts so close that any motion given to one part will be 
transmitted to the other without slipping, as a contact 
between two curved surfaces so perfect that their recip- 
rocal pressure is sufficient to transmit any motion of rota- 
tion applied to one to the other without the interposition 
of any locking device, as a key, gib, splice, screw-thread, 
set-screw, or polygonal surface, (b) A close fit produced 
by a pressure sufficient to retain a part in its position 
when acted upon by its weight alone. 
friction-tube (frik'shon-tub), n. Milit., a tube 
used in firing cannon, sufficient heat being 
generated in it by friction to ignite friction- 
powder. [Eng.] Called friction-primer in the 
United States service. 
friction-Wheel (frik'shon-hwel), n. In mach. : 
(a) A form of slip-coupling applied in cases 
where the variations of load are sudden and 
great, as in dredging-machinery, etc. in the 
form illustrated a strong pulley, B, is keyed on the driving- 
shaft, and on the circumference of this a wheel, A, isfitted, 
with a series of friction-plates, a, a, a, interposed, and re- 
tained in recesses formed in the eye of the wheel. Behind 
each of these plates a 
set-screw, b, is inserted, 
which bears against the 
back of the plate, and 
can be tightened at 
pleasure to regulate the 
degree of friction re- 
quired for the ordinary 
work ; but should the 
pressure on the circum- 
ference of the wheel A 
exceed this, the plates 
slide upon the circum- 
ference of the pulley B, 
which continues to re- 
volve with the shaft, 
and the wheel itself re- 
mains stationary. (5) 
One of two simple 
wheels or cylinders intended to assist in dimin- 
ishing the friction of a horizontal axis. The 
wheels are simply plain cylinders, carried on parallel and 
independent axes. They are disposed so as to overlap 
pair and pair at each end of the main axis, which rests in 
the angles thus formed by the circumferences. The axis, 
instead of sliding on a fixed surface, as in ordinary cases, 
carries around the circumferences of the wheels on which 
it is supported with the same velocity as it possesses itself, 
and in consequence the friction of the system is propor- 
tionally lessened. 
A late improvement in what are called friction-wheels 
. . . consists of a mechanism so ordered as to be regu- 
larly dropping oil into a box which encloses the axis, the 
nave, and certain balls upon which the nave revolves. 
Paley, Nat. Theol., viii. 
Friday (fri'da), n. [< ME. Friday, Fryday, Fri- 
dai, yrideie, etc., < AS. Frige dag, also contr. 
Frigdasg (= OFries. Friaendei, Friendei = MD. 
Vridach, D. Vrijdag = MLG. Vridach = OHG. 
Friatag, Frijetag, MHG. Vritac, G. Freitag), 
Friday; < AS. Frige, gen. of "Friou (found 
otherwise only as a common noun, in gen. pi. 
friga, dat. pi. frigum, love) = OHG. Fria = 
Icel. Frigg (gen. Friggjar, Frigg, Latinized 
Frigga, a Teutonic goddess, in part identified 
with the Roman Venus), AS. Frige dceg, etc., be- 
ing a translation of the Roman name of this 
A 
Friction-wheel. 
friend 
day, dies Veneris or Vcncris dies (> It. Ve-ucrd't 
= Cat. J>ircndrcs = Sp. Viernes = F. IV niln.-li, 
Friday; the Pg. term is nc.r/n-j'i-im, lit. sixth 
fair, i. e., day). The name 1'm/i/ appears in 
Icel. only as the name of a goddess, the wife of 
Odin, different from t'rcyja; in AS. from the 
same root as free, friend, frith^, etc. ; cf. ,Skt. 
priyd, f.. one beloved: see free, J'rinnl, /n'tf/i.] 
The sixth day of the week. Friday it the Moham- 
medan sabbath or "day of assembly." It is said in the 
Mohammedan traditions to have been established by di- 
vine command as a day of worship for Jew mid Christian 
alike, as being the day on which Adam was created and 
received into Paradise, the day on which he was expelled 
from it, the day on which he repented, and the clay on 
which he died. It will, according to the same traditions, 
be the day of the resurrection. In the Roman and East- 
ern and Anglican churches, all Fridays except Christmas 
day (when it occurs on Friday) are generally observed aa 
fasts of obligation or days of abstinence, in memory of 
the crucifixion of Christ, an event 1 which is more espe- 
cially commemorated annually on Good Friday (see below). 
In most Christian nations Friday is popularly regarded 
with superstition, and is considered an unlucky day for 
beginning any enterprise ; to spill more or less salt on Fri- 
day is considered an especially bad omen. Until recently 
it was common for criminals under sentence of capital 
punishment to be executed on Friday ; hence Friday is 
sometimes called hangman's day. 
After hym we honpureth Venus meat, that Frie yclepud 
ys in onre tonge, & in the wyke Fridtni for hym ywys. 
Itub. of Gloucester, p. 112. 
Selde is the Frydat/ al the wyke ilike. 
Chaucer, Knight's Tale, 1. 681. 
The duke, I say to thee again, would eat mutton on /'<<- 
days. Shak., M. for M., iii. 2. 
Columbus sailed from Spain on Friday, discovered land 
on Friday, and reentered the port of 1'alos on Friday. 
Preacott, Ferd. and Isa., i. 19. 
Black Friday. (<it) Good Friday : so called because on 
that day, in the Western Church, the vestments of the 
clergy and altar are black, (b) Any Friday marked by a 
great calamity : with special reference in England to Fri- 
day, December 6th, 1745, the day on which news reached 
London that the young pretender Charles Edward bad 
reached Derby ; or to the commercial panic caused by the 
failure of the house of Overend and (iiirney, Slay llth, 
1866; anil in the United States to the sudden financial panic 
and ruin caused by reckless speculation in gold on the ex- 
change in the city of New York on Friday, September 24th, 
1869 ; or to another similar panic there, which began Sep- 
tember 18th, 1873. Golden Friday, (n) The Friday in 
each of the emlier-weeks. F. G. Lee, Eccles. Terms. (It) 
Among the Nestorians, the Friday after Whit-Sunday. 
The Friday after Pentecost is called Gulden Friday, and 
is a high Festival. J. il. Keale, Eastern Church, i. 750. 
Good Friday, the Friday before Easter, a holy day of the 
Christian church, in memory of Christ's crucifixion, of 
which this day is taken as the anniversary. The early 
church observed it as a strict fast ; in the church services 
doxologies were omitted, no music except the most plain- 
tive was allowed, and the altars were stripped and draped 
in black. At present, in the Greek anil Unman Catholic 
churches, Good Friday is a solemn fast ; and it is also ob- 
served with special services and prayers by the Church 
of England, and the Protestant Episcopal Church in the 
United States, and by the Lutherans, German Keformed 
Church, Moravians, and many Methodists. 
The tother salle be Godfraye, that Gode schnlle revenge 
One the Gltd Frydaye with galyarde knyghtes. 
Morte Arthurs (E. E. T. S.), 1. 3432. 
Cheer up, my soul, call home thy sp'rits, anil bear 
One bad Gootl-friday ; f ull-month'd Easter's near. 
Qtiarlex, Emblems, v., Epig. 7. 
Good-Friday bun, a cross-bun. Holy Friday, Friday 
in an ember-week. 
Friday-facedt (fri' da-fast), a. Melancholy- 
looking; dejected. 
Marry, out upon him ! what a friday-fac'd slave it is ! 
I think in my conscience his face never keeps holiday. 
Wily Beguiled (Hawkins's Eng. Drama, III. 356). 
fridge 1 ! (frij), . i. [Assibilated form of equiv. 
frig (cf. fidge, assibilated form oifnj^); cf. E. 
dial, frichc, brisk, nimble, active, < ME. frike, 
frek, active : see freck 1 and frig.~\ To move 
rapidly ; frisk or dance about. 
The little motes or atoms that fridge and play in the 
beams of the sun. Hath/well, Mclampronrca (1681), P- 3. 
fridge 2 ! (frij), v.t. [E. dial.; origin uncertain; 
perhaps another form, assimilated to fridge 1 , of 
fray, ult. < L. fricare, rub : see/ra^ 2 .] To rub ; 
fray. 
You might have rumpled and crumpled, and doubled and 
creased, and fretted aud/nVfyed the outside of them [jer- 
kins] all to pieces. Sterne, Tristram Shandy, ii. 116. 
fridstolet (frid'stol), n. See frithstool. 
frie 1 !, i'. 
frie 2 t, n. 
fried-chicken (frld'chik'en), n. Same as friar's 
chicken (which see, under friar). 
friedelite (fre'del-It), n. [Named aftera French 
chemist, Ch. Friedel.~] A silicate of manganese 
containing a little chlorin, occurring in rhom- 
bohedral crystals and in cleavable masses of a 
rose-red color at Adervielle in the department 
of Hautes-Pyr6nes, France. 
friend (frend), n. [Early mod. E. also frend, 
freind; < ME. frend, freond, < AS. freoiid (pi. 
