diagonal 
One angle U anothor not adjacent, within any 
fijr, lr ,.. 2. He ing in an oblique direction; lying 
<>lili(|uely. 3. Marked by "1'li'jiio lines: as, <//- 
tli/iiinil elolh. Diagonal bellows, In nrgan -'/i7./i,/./. 
a bellows whose tun siiles atr |'l:iccil at HI) alible ti) each 
other-. dUinuuMn'd from /,../-. -,!// h,iiu,n. - Diago- 
nal bond, see imndi. Diagonal brace or diagonal 
tie. See. nniile-krace (a). Diagonal cloth, a (willed 
fabric so nun* that the diagonal ridges are somewhat 
j rominent and noticeable. Kspecially () A soft ma- 
terial used us a ground for embroidery, generally made 
very wide, and dyed In plnlii colors without pattern, 
(ft) A material for men's wear especially for coats and 
waisU-oats. -Diagonal couching. See cimMngl, 5. 
Diagonal plane, i but., any vertical plane bisecting a 
(lower which Is not an uteropoiterior plane or at rii;ht 
angles to that plane. Diagonal point of a quadran- 
gle, one of the three points, other than the points of the 
quadrangle, where the six lines intersect. Diagonal 
scald, a ruler on which is drawn a set of parallel lines 
marked off Into equal divisions by cross-lines, one of the 
divisions at one extremity of the ruler being subdivided 
p 
\ 
1 
s 

Diagona 

1 Scale. 
S 
by parallel lines drawn obliquely at equal distances across 
the parallels. Such a scale facilitates laying down small 
fractions of the unit of measurement. Thus, if, In the 
figure, the distance from to 10 one inch Is divided 
into 10 equal parts, the diagonal which ends at cuts off 
upon the parallel lines ,J , ,!<;, etc., inch respectively ; 
the next diagonal cuts olf f,i r ,, M, etc. Diagonal tri- 
angle, a triangle formed by the three diagonals of a com- 
plete quadrilateral, or the three diagonal points of a 
quadrangle. 
II. n. 1. A straight line drawn from one 
angle to or through another, not adjacent, in 
any plane or solid figure. 2. Any oblique line. 
I moved as in a strange diagonal, 
And maybe neitherpleased myself nor them. 
Tennyson, Princess, Conclusion. 
Specifically 3. In chess, checkers, etc., a line 
of squares running diagonally across the board. 
See chess 1 . 4. Same as diagonal cloth, espe- 
cially in the United States : a term introduced 
about 1875. Dexter diagonal, in math., a diagonal 
from the upper left-hand to the lower right-hand angle. 
Principal diagonal, that diagonal which passes through 
the angle considered as the first. See determinant, 3. 
diagonal-built (dl-ag'o-nal-bilt), a. Built, as a 
boat, in such a way that the outer skin is formed 
by two layers of planking atright angles to each 
other and making an angle of about 45 with the 
keel, in opposite directions. 
diagonally (di-ag'o-nal-i), adv. In a diagonal 
direction; crosswise. 
The next leaf may be single ; stitch it across with double 
silk diagonally, and cross those stitches with others. 
I. Walton, Complete Angler, t 6. 
diagonialt (di-a-go'ni-al), a. [< Gr. i 
~E.-al: see diagonal.]" Diagonal; diametrical: 
as, "diagonial contraries," Milton. 
diagram (di'a-gram), n. [< P. diagramme, < L. 
(litujraaiina, a scale, the gamut, in music, < Gr. 
ita)paufta(r-), that which is marked out bylines, 
a figure, a written list, register, decree, the ga- 
mutj or a scale, in music, < itaypafyetv, mark out 
by lines, draw, describe, < <5i, across, through, 
+ ypa<f>e.tv, write: see granfl, graphic.] 1. In 
geom., a drawing or scheme delineated for the 
purpose of demonstrating the properties of any 
figure by observations on the geometrical rela- 
tions of its parts. 
Many a fair precept in poetry is like a seeming demon- 
stration in the mathematicks : very specious in the dia- 
gram, but failing in the mechanick operation. Dryden. 
2. An illustrative figure giving only the out- 
lines or a general scheme (not an exact repre- 
sentation) of the object ; a figure for ascertain- 
ing or exhibiting certain relations between ob- 
jects under discussion by means of analogous 
relations between the parts of the figure. 
Dr. Dalton, in his Elements of Chemistry, . . . published 
a large collection of diagrams, exhibiting what he con- 
ceived to be the configuration of the atoms in a great 
number of the most common combinations of chemical 
elements. Wheuxll, Hist. Scientific Ideas, vii. :;. 
A diagram is a figure drawn in such a manner that the 
geometrical relations between the parts of the figure help 
ns to understand relations between other objects. 
Clerk Maxmll, Eucyc. Brit., VII. 149. 
3. In old nitwit; a table representing all the 
sounds of the system; a musical scale __ Accel- 
eration-diagram. (u) A diagram in which the relative 
positions of points represent in magnitude and direction 
the relative acceli rat ions of particles. Also called fir 
Han-polygon. (6) A diagram in which the accelerations of 
particles are represented in magnitude and direction by 
lines drawn from points showing the ]>oMii,,, LS , it those par- 
ticles Configuration-diagram,:! ilia JIMMI "liich shows 
the relative positions of the part-Jot' a system by means of 
the relative situations of points, but does not, like a plan, 
1589 
show the forms of different bodies. Contrast-diagram, 
a color-diagram show ing the relations of contrast ti. I u. , n 
aolon. Displacement-diagram, (n) A diagram in 
which the reiatn. positions ofpoinU represent in magni- 
tude and .lire tion the relative displacements of particles. 
d tier called di*i>{<t<'<*tnent-polyg<m. (b) A diagram in 
which the displacements of particles are represented in 
magnitude aid direction liy linen drawn from points show- 
ing the positions of those particles. Force-diagram, a 
diagram in which the lines ot action of forces are rcpre- 
Kenteil by lines. Frame-diagTam I a diagram of a frame 
Inwhichthepo-itioiisoi the axes of the joints are shown by 
points, while the rigid or elastic connections are shown by 
lines between thcpoints. Suchadiagram of the configura- 
tion of the frame is, in graphical statics, united with a dia- 
gram of the forces, the latter being so resolved that all 
the components pass through joints. By means of a sec- 
ond diagram, the frame-diagram is then completed by the 
addition of the resultant diagram. Funicular diagram, 
a diagram in which every joint of a frame is represented 
by a funicular polygon, and every link In the frame by a 
line, the Hide of a funicular polygon or polygons. Also 
called strest-diayram. Indicator-diagram, the diagram 
traced by the steam-indicator. The diagram is a curve 
having rectangular coordinates of which the abscissas rep- 
resent distances of piston* travel from the beginning of the 
stroke and the ordlnates pressures at these distances. 
The area of the diagram measures the total work per- 
formed by the piston during the stroke. This work, ex- 
pressed In foot-pounds, divided by Joule's equivalent, 
gives the heat-equivalent of the work performed, in Brit- 
ish thermal units, (See indicator.) These diagrams may 
be obtained tram nearly all kinds of heat-engines. Also 
called (with the paper on which it is traced) indicator-card. 
Metrical diagram, a figure drawn to scale from nu- 
merical data lor t he purpose of ascertaining the values of 
other quantities by measurement. Newton's diagram, 
a diagram in which the points represent colors, weights 
attached to points represent luminosities, and collinear 
points represent colors which can be produced by mixtures 
of two colors. Reciprocal diagrams, two diagrams 
such that to every point of concourse of lines in either cor- 
responds a closed polygon in the other. Resultant dia- 
gram, a line upon a force-diagram showing the direction 
and position of the resultant of the forces. Stereoscopic 
diagrams, a pairof diagrams, perspective representations 
of a solid diagrammatic figure, intended to be optically 
combined by means of a stereoscope. Stress-diagram. 
Same ta/unifidar diagram. Velocity-diagram, a dia- 
gram defined like an acceleration-diagram by substituting 
velocity for acceleration. (See also color-diagram.) 
diagram (di'a-gram), v. t. [< diagram, .] To 
draw or put into the form of a diagram ; make 
a diagram of. 
They are matters which refuse to be ... diagramed., 
which Logic ought to know she cannot speak of. Carlylc. 
diagramically(dl-a-gram'i-kal-i), adv. Ashort- 
ened form of (Ungrammatically. [Rare.] 
The folds of her skirts hanging diagram ically and stiffly. 
Philadelphia Timel, April 18, 1885. 
diagrammatic fdl"a-gra-mat'ik), a. [< Gr. as 
if *6iaypa/ipaTtKOs, (. otaypa/t/iafr-), a diagram.] 
Pertaining or relating to, or of the nature of, a 
diagram ; represented by means of a diagram ; 
consisting of a diagram ; more generally, sche- 
matic anil abstract. 
Aristotle undoubtedly bad in his eye, when be discrimi- 
nates the syllogistic terms, a certain diagrammatic con- 
trast of the figures. Sir W. Hamilton. 
Diagrammatic reasoning, reasoning which proceeds 
by first constructing a diagram or other visible scnema by 
means of given relations, and then observing in this dia- 
gram other relations not made use of, as such, in con- 
structing the diagram. 
diagrammatically (di'a-gra-mat'i-kal-i), adv. 
After the manner of a diagram j by means of a 
diagram or diagrams ; schematically. 
diagrammatize (di-a-gram'a-tiz), v. t.; pret. 
ana pp. diagrammatized, ppT"diagrammatizing. 
[< Gr. oiuypau[ia(T-), a diagram, + E. -ire. Cf . Gr. 
oiaypafiuifctv, divide by lines, play at draughts.] 
To represent by a diagram ; put into the form 
of a diagram. Also spelled aiagrammatise. 
It can be diagrammatised as continuous with all the 
other segments of the subjective stream. II iml, IX. 18. 
diagrammeter (di-a-gram'e-ter), n. [< Gr. otd- 
ypafi/ia, diagram, +' fitrpov, a measure.] An in- 
strument for measuring the ordinates of indi- 
cator-diagrams, 5 seconds long, and used much 
after the manner of a parallel rule. E. D. 
diagraph (di'a-graf ), n. [< Gr. Staypa^etv, mark 
out by lines: "see diagram.'] 1. An instrument 
by which persons without Knowledge of draw- 
ing or perspective can reproduce the figures of 
objects before their eyes, it consists of a carriage 
for a pencil governed by a system of cords and pulleys work- 
ing at right angles to one another, and set in motion by the 
movement of a pointer, which is passed by the operator, 
who is careful to keep his eye at a fixed point of view. 
around the apparent outlines of his subject The pencil 
describes on the paper the exact motions of the pointer, 
and thus reproduces the desired object 
2. A combined protractor and scale used in 
plotting. E. II. Knight. 
diagraphic, diagraphical (di-a-graf'ik, -i-kal), 
a. [< (!r. i!/a}/xi0m<, mark out by lines: see 
<liii<n'iii>li andoropWe.] Descriptive. Imp. Diet. 
diagraphics (di-a-graf 'iks), . [PL of dia- 
!/rni>hic : see -ics.] The art of design or draw- 
ing. 
dial 
diagrydiate (di-a-grid'i-at), n. [< diagrydium 
+ -ate 1 .] A strong purgative in which scam- 
mony is an in^inli. nt. 
diagrydium (>ti-,;i-t,Tid'i-um), n. [NL. ML., 
also (liiigi-nliiiiH, < I'L. diayrydium, < Gr. <V 
diov, the juice of a purgative plant, Convolvulus 
scammonia.] An old commercial name for 
scammony. 
diagyios (di-a-ji'i-os), a. [LL. diagyios (Mar- 
tianus Capelja), < Gr. ttaytxoc. (Aristides Quinti- 
lianus) for diyvtor., of two members, < it-, two-, 
+ yviav, limb, member.] In anc. pros., consist- 
ing of two members : a distinctive epithet of 
the paeon or peonic foot in the form commonly 
known as the C'retic. Paeon diagyios, the ordinary 
cretlc, a prconic foot of two semeia or divisions (-- *- ;, 
as distinguished from the paa>neiiiuat\u(* \ I -^- ) 
a compound foot of double the magnitude, divided Into 
four parts. See epibattit and i*ron. 
diaheliotropic (di-a-he'li-o-trop'ik), a. [< Gr. 
ii&, through, across, transversely, + E. helio- 
tropic, q. v.J In bot., turning transversely to 
the light, as the stem or other organs of a 
plant ; pertaining to diaheliotropism. 
The movements of leaves and cotyledons . . . when 
moderately Illuminated are diahfliotropic. 
Darwin, Movement In Plants, p. 445. 
diaheliotropism (dl-a-he-li-ot'ro-pizm), n. [< 
diaheliotrop-ic + -ism'.'} In bot., the tendency of 
a plant or of the organs of a plant to assume a 
more or less transverse position to the light. 
As all leaves and cotyledons are continually circumnu- 
tating, there can hardly be a doubt that diaheliotropitm 
results from modified circumnutation. 
Darurin, Movement in Plants, p. 564. 
dial (di'al), . [< ME. dial, dyal, a dial, < ML. 
dialis, daily (cf. diale, as much land as could 
be plowed "in a day), < L. dies, a day: see deity. 
From L. dies come also diary, diurnal, journal, 
journey, etc. ; cf. rfte(2.] 1. An instrument for 
indicating the hour of the day by means of a 
shadow thrown upon a graduated surface. For 
dials with a style or gnomon, see sun-dial; for 
portable dials, see ring-dial, poke-dial, and sola- 
rium. 
Read on this dial, how the shades devour 
My short liv'd winter's day. 
(Juarlen, Emblems, IIL 13. 
The sly shadow steals away upon the dial, and the quick- 
est eye can discover no more but that it is gone. 
Glanrille. 
2. The face of a clock or watch, upon which the 
hours and minutes are marked, and over which 
the hands move. 
We live in deeds, not years ; in thoughts, not breaths ; 
In feelings, not in figures on a dial. 
P. J. Bailey, Festus : Scene, A Country Town. 
Hence 3f. A timepiece of any kind ; a clock 
or watch. In the first extract Shakspere may have 
meant a portable dial of the kind described below ; but 
in the second a watch of some kind seems to be clearly 
indicated. 
And then he drew a dial from his poke ; 
And looking on it with lack-lustre eye, 
Says, very wisely, "It is ten o'clock; 
Thus we may see," quoth he, "how the world wags." 
Khalc., As you Like It, ii. 7. 
Then my dial goes not true. Sltak., All's Well, II. B. 
4. Any plate or face on which a pointer or an in- 
dex moves, marking revolutions, pressure, ete., 
according to the nature of the machinery of 
which it forms part : as, the dial of a steam- 
gage, gas-meter, or telegraphic instrument. 
5. In teleg. and Itorol., an insulated stationary 
wheel exhibiting upon its face letters, numer- 
als, or other characters. 6. The lettered or 
numbered face-plate of a permutation-lock. 
7t. A mariners' compass. [Rare.] 
W are not to Ceres so much bound for Bread . . . 
As (Signior Klanio) to thy witty triall. 
For first inuenting of the Sea-mans Diall. 
Sylvetter, tr. of Du Bartas's Weeks, I. 3. 
8. In mining, a compass or graduated circle 
with a magnetic needle, arranged for under- 
ground surveying where great accuracy is not 
required. [Eng.] 9. A lapidaries' instrument 
for holding a gem while it is being cut. It 
carries the dot to which the gem is directly 
fixed Azimuth dlaL See azimuth. Catoptric dial. 
See catoptrir. Center of a dial. *ee center^. Cylin- 
drical dial, a dial drawn on a cylindrical surface. De- 
clining dial, a dial the plane of which intersects the 
horizon in a line not directed to a cardinal point; a dial 
the azimuth of whose plane Is neither east, west, north, 
nor south. Also called declintr. Direct dial, a dial 
the azimuth of w hose plane is east, west, north, or south. 
East dial, a direct dial which is exposed toward the 
east. Equatorial dial. Same as equinoctial dial. 
Equinoctial dial, a dial whose plane is perpendicular 
to the earth's axis. Erect dial, a dial whose plane Is 
vettical Fixed dial, a dial which is intended to have a 
fixed position, and to show the time by means of the hour- 
