groundsill 
soyle, etc.; < ground^ + W.] 1. The timber 
of a building which lies next to the ground; 
the ground-plate ; the sill. 
They first vndennined the groundsills, they lieate downe 
the wallea, they vntloored the loftes, they vntiled it and 
pulled downe the roofe. 
1'uttenharn, Art of Eng. Foesie, p. 186. 
Will ye build up rotten battlements 
On such fair groundsels? 
Middleton and Rowley, World Tost at Tennis. 
In his own temple, on the grunsel edge, 
Where he fell Hat, and shamed his worshippers. 
Milton, P. L., i. 460. 
I saw him then with huge, tempestuous sway 
He dasht and broke 'em on the grundsil edge. 
Addison, .-Kneid, iii. 
2. In mining, the bottom piece of a wooden 
gallery-frame. 
ground-sloth (ground'sloth), . An extinct 
terrestrial edentate mammal of a group repre- 
sented by the megatherium and its allies, from 
some member of which the modern arboreal 
sloths are supposed to be descended ; one of the 
family Megatheriidie in a broad sense. 
ground-sluice (ground'slos), . See sluice. 
ground-snake (ground'snak), n. 1. A worm- 
snake ; any small serpent of the genus Carpho- 
pliiops, a few inches long, as C. amcenus, C. ver- 
mis, or C, Helenas. [U. S.] 2. A snake of the 
family Coronellidce, Coronella australis. [Aus- 
tralia. ] 
groundsopt, groundsopet, n. [Early mod. E. 
groundesoppe, < ME. growndesope, gruudsope, 
< AS. grmidsopa (= D. grondsop, grondsap = 
MHG. gruntsophe, G. grundsuppe), dregs, lees, 
grounds, < grund, ground, + "sopa, *soppa, sop : 
see ground^ an d sop, n. ] Dregs ; lees ; grounds. 
Palsgrave. 
ground-Sparrow (ground'spar"o), n. Aground- 
bird ; one of several small grayish and spotted 
or streaked sparrows which nest on and usually 
keep near the ground, as the savanna-sparrow 
and the grass-finch, bay-winged bunting, or ves- 
per-bird. [New Eng.] 
ground-squirrel (ground'skwur"el), n. 1. A 
terrestrial squirrel-like rodent, as one of the 
genera Spermophilus and Tamias: especially 
applied in the United States to species of the 
latter genus, as Tamias striatus, the hackee or 
chipmunk. In the United States, where there are more 
kinds of ground-squirrel than in any other part of the 
world, those of the genus Spermophilus are mostly called 
gophers, by confusion with the entirely different animals 
of the genera Geomys and Thomomys. See chipmunk, 
gopher, and spermophile. 
2. An African squirrel of the genus Xerus. 
Sclater. 
ground-starling (ground 'star* ling), n. An 
American meadow-lark; a bird of the family 
Icteridce and subfamily Sturnellince, as Sturnella 
magna or Trupialis militaris. 
ground-strake (ground'strak), n. Same as gar- 
board-strake. 
groundswellt, n. An obsolete variant of ground- 
sen. 
ground-swell (ground'swel), n. A broad, deep 
swell or rolling of the sea, occasioned by a dis- 
tant storm or heavy gale, and sometimes also 
by distant seismic disturbances: sometimes 
used figuratively of a rolling surface of coun- 
try, and also of a rising wave of sound or of 
emotion. 
Groundswells are rapidly transmitted through the wa- 
ter, sometimes to great distances, and even in direct op- 
position to the wind, until they break against a shore, or 
gradually subside in consequence of the friction of the 
water. Brnnde and Cox. 
The vessel leaned over from the damp night-breeze, and 
rolled with the heavy ground-swell. 
S. B. Dana, Jr., Before the Mast, p. 4. 
ground-table (ground'ta'bl), n. In arch., same 
as earth-table. 
ground-tackle (ground'tak*!), n. Naut., a gen- 
eral term for the anchors, cables, warps, springs, 
etc., used for securing a vessel at anchor. 
ground-throw (ground'thro), n. See throw. 
ground-thrush (ground'thrush), n. 1. A bird 
of the genus Cinclosoma. 2. A thrush of the 
genus Geocichla. No American thrushes have been 
placed in this genus, except by Seebohni, who refers to it 
the varied thrush or Oregon robin, as G. ncevia; the Alas- 
kan ground-thrush, a bird usually called Turdus ncevius 
or Hesperocichla ncevia ; and a Mexican form, the Turdiii 
pinimla of Sclater. A few of the ground-thrushes pre- 
sent the anomaly of 14 tail-feathers, as G. varia, form- 
ing with most authors the type of another genus, Oreo- 
cincla. Other differences among the species have also been 
recognized as generic, whence the names Zoothera, Tur- 
dulm, Cichlopasser, Cham&tylas, and f'sophocichla, the 
type-species of which genera are respectively G. mon- 
ticola, G. wardi, G. terrestris, G. compsonola, and G. sirwn- 
sis. The G. or Oreocincla mrta is White's ground-thrush of 
Siberia, China, Janan. and southward to the Philippines; 
2637 
it has also been found as a straggler in Europe. Nearly 
related to this are G. hancii and G. horsjieldi, respectively 
tin 1 Kormosan and the Javan ground-thrush. G.dauma,the 
Dauma thrush of Lutham, is found in the Himalayas and 
southward in India ; G. lunttlata is Smith Australian ; G. 
heinel is North Australian ; G. macrorhyncha is Tasmauian ; 
G. nilyirifiixis is confined to the mountains of southwestern 
India ; G. papuensis inhabits New Guinea ; G. imbricata 
is Ceylonese ; G. mvllisirima and G. dixoni arc Himalayan 
and Indian. G. monticola, G. marginata, and G. andro- 
medtetnrm a group of saw-billed ground-thrushes (Zoothe- 
ra) of the Himalayas, India, Java, etc. Among African 
forms are G. princei of Guinea, G. compsonota of the Ga- 
boon (type of Chamaetylas), G. bimltata of the Gold Coast, 
G. gurneyi and G. guttata of Natal, G. crossleyi of the 
Cameroons, and G. piagii of the Uganda country. The 
Abyssinian ground-thrush is G. simeniis, which with the 
South African G. litsitsirupa (formerly called Turdus 
strepitans) represents a division of the genus called Pso- 
phocichla. The Macassar ground-thrush is G. erythronota 
of Celebes. G. interpres, figured by Temminck in 1828 as 
Turdus interpres, is supposed to be the type of Geocichla; 
it is found in Java, Sumatra, and Lombok. The spotted 
ground-thrush is G. spiloptera of Ceylon ; G. peroni in- 
habits Timor. G. cyanotus is the white-throated ground- 
thrush of central and southern India. G. citrina is a bird 
long known as the orange-headed thrush (Latham), in- 
habiting the Himalayas from Nepal to Assam, and mi- 
grating southward in India, and even to Ceylon. G. ru- 
becula is confined to Java ; G. andamensis inhabits the 
Andaman islands; G. albogularis, the Nicobars; G. inno- 
tata is the Malay ground-thrush ; G. wardi is the pied 
ground-thrush of India (type of Turdulus). Q. sibirica is 
a species known to the early writers as the white-browed 
thrush (Turdus sibiricitf or T. auroreus), of wide distri- 
bution in Asia and neighboring islands. An isolated 
form is Kittlitz's ground-thrush, G. terrestris, of the Bonin 
islands, forming the type of the genus Cichlopasser. 
3. pi. The old-world ant-thrushes; the pittas 
or Pittid(e. 
groundwallt, [< ME. groundwalle, grounde- 
walle, grundwalle, grundwal, < AS. grundweal 
(= MHG. gruntwal = Sw. grundvdl = Dan. 
grundvold), a foundation, < grund, ground, + 
weall, wall.] A wall as foundation ; a founda- 
tion. 
Bot for-thi that na were may stand, 
Witouten grundwalle to be lastand. 
MS. Cott. Vespas., A. iii. f. S. (Halliwell.) 
groundways (ground'waz), n. pi. In ship- 
building, a substantial foundation of wood or 
stone for the blocks on which a vessel is built. 
ground-wheel (ground'hwel), n. Any wheel in 
a harvester, grain-drill, or other machine that, 
while it assists to support the machine, imparts 
motion to the other parts of the machine, as to 
the cutters, feeders, etc. 
groundwork (ground'werk), n. That which 
forms the foundation of something ; the foun- 
dation or basis ; the fundamental part, princi- 
ple, or motive : used of both material and im- 
material things. 
Behold, how tottering are your high-built stories 
Of earth ; whereon you trust the ground-work of your 
glories. Quarles, Emblems, i. 9. 
The morals is the first business of the poet, as being the 
groundwork of his instruction. Dryden. 
Treacle and sugar are the groundwork of the manufac- 
ture of all kinds of sweet-stuff : hard-bake, almond toffy, 
black balls, etc. 
Mayhew, London Labour and the London Poor, I. 215. 
group 1 (grop), n. [= D. groep = G. Dan. gruppe 
= Sw. grupp, < F. groupe, < It. gruppo, groppo, 
a knot, heap, group, bag (of money), = Sp. gru- 
po, gorupo, a knot, cluster, group; prob. an- 
other form of the word which appears in F. 
croupe, the croup or crupper of a horse, orig. a 
' bunch,' from the LG. or Scand. form of E. crop, 
the top of a plant, etc. : see crop and croup*.] 
1. An assemblage of persons or things ; a num- 
ber of persons or things gathered together with 
or without regular interconnection or arrange- 
ment ; a cluster. 
In groups they stream'd away. 
Tennyson, Princess, Conclusion. 
We may consider as a group those molecules which at 
a given instant lie within a given region of space. 
H. W. Watson, Kinetic Theory of Gases, Int., p. vi. 
The Arab kindred group or hayy, as we know it, was a 
political and social unity, so far as there was any unity in 
that very loosely organized state of society. 
W. R. Smith, Kinship and Marriage, p. 36. 
It is impossible thoroughly to grasp the meaning of any 
group of facts, in any department of study, until we have 
duly compared them with allied groups of facts. 
J. Fiske, Amer. Pol. Ideas, p. 6. 
2. In the fine arts, an assemblage of figures 
which have some relation to one another and 
to the general design ; a combination of several 
figures forming a harmonious whole. 
The famous group of figures which represent the two 
brothers binding Dirce to the horns of a mad bull. 
Addition. 
We would particularly draw attention to the gnntp which 
was formerly thought to represent Eurytion and Deida- 
meia, but is now identified with the group of a Centaur 
carrying off a virgin described by Pausanias. 
C. T. Newton, Art and Archieol., p. 362. 
group 
3. In scientific classifications, a number of in- 
dividual things or persons related in some defi- 
nite or classificatory way. 
The progress of science is the successive ascertainment 
of invariants, the exact quantitative determination of 
groups. Every clearly defined phenomenon, every law of 
phenomena, is the establishment of an invariant group. 
G. 11. Lewes, Probs. of Life and Mind, II. ii. 107. 
The fact lately placed beyond all doubt by Kbnig and 
Dieterici, that those that are born color-blind fall natu- 
rally into two great groups, the red and green blind. 
Amer. Jour. Psychol., I. 311. 
Specifically (a) In zool., any assemblage or classificato- 
ry division of animals below the kingdom and above the 
species : generally said of intermediate or not regularly 
recognized divisions, or by way of non-committal to the 
exact taxonomic value of the division thus indicated. (6) 
In geol., a division in the geological sequence or classifi- 
cation of the stratified fossiliferous rocks Inferior in value 
to a system or series. See system. 
4. In music: (a) A short rapid figure or divi- 
sion, especially when sung to a single syllable. 
(6) A section of an orchestra, comprising the 
instruments of the same class: as, the wood-wind 
group. 5. In math., a set of substitutions (or 
other operations) such that every product of 
operations of the set itself belongs to the set; a 
system of conjugate substitutions ; a set of per- 
mutations resulting from performing all the 
substitutions of a conjugate system upon a 
series of elements ; a set of functions produced 
by the n operations of a group of operations 
from n independent functions, called the fun- 
damental system of the group. The order or de- 
gree of a group is the number of substitutions it contains ; 
its index is this number divided into the whole number 
of permutations of the elements of the substitutions. 
Abelian group, in math., an orthogonal group whose 
substitutions transform the function 
Into itself, except for a constant factor. Alternating 
group, a group of alternating numbers. Antipotentiai 
group, in math., a group each of whose substitutions is 
formed from a given group of substitutions, *j, s%, 8 ."j> *4 
etc., as follows: Beginning with any one of these substi- 
tutions, (, we find a cycle of substitutions *, , 8 V , etc., 
such that 
8 
JS 
1 = *'C" l =, etc., 
TT 
and then each of the cyclic substitutions (a, ft, 7, etc.) is 
a substitution of the antipotential group. Associate 
groups, in math., groups of associate substitutions. 
Cambrian group. See Cumbrian. Chemung group, 
the name given By the geologists of the New York sur- 
vey to certain rocks of Devonian age largely developed 
in Chemung county and other southern counties of New 
York, and further south through the Appalachian region. 
They are chiefly sandstones and coarse shales, and the 
series has a thickness of from 1,000 to 1,500 feet in New 
York, and a still greater In Pennsylvania. Cincinnati 
group. See Hudson River group. Clinton group, the 
name given by the New York geologists to that part of the 
Upper Silurian series which lies between the Medina sand- 
stone and the Niagara group. The rock is chiefly an ar- 
gillaceous sandstone, much of which is quite hard, and di- 
vided into layers having a peculiar wavy or knobby surface. 
The name is given with reference to the town of Clinton in 
Oneida county. New York. This group is of special interest 
from the occurrence in it of important deposits of iron ore. 
See Clinton ore, under ore. Commutative groups, in 
math., two groups such that the product of two substitu- 
tions belonging to one and the other is independent of the 
order of the factors Composite group, in math., one 
which contains a self -conjugate subgroup other than the 
group itself and unity. Congruence group of the 
?! li degree, in math., one which consists of all substitu- 
lons (ao> + /3)/(yiu + 8X where aS /Sy=l, and where a, f, 
y, & are whole numbers, satisfying congruences to the 
modulus q. Continuous group, in math. : (a) A group 
of substitutions infinite in number and continuously con- 
nected. (6) A group of infinitely many but discrete opera- 
tions, among which infinitely small transformations occur. 
Cremona group. In math., a group ol Cremona substi- 
tutions. Cretaceous group. See cretaceous. Cyclic 
group, in math., a group composed of iterations of a 
single operation. Dihedral group, in math., a group of 
rotations in three-dimensional space by which a regular 
polygon is brought to coincidence with its former position. 
Discontinuous group, in math., a group of substi- 
tutions not continuously connected. Double pyramid 
group, in math,, same as dihedral group. Exchange- 
able groups, in math., same as commutative groups. Ex- 
tended group, in math., a group of rotations extended 
by the addition of operations of perversion. Finite 
group, in math., a group the number of whose substitu- 
tions is finite. Forest-bed group. See forest. Fuch- 
sian group, in math., a group of linear transformations 
of a quantity /, 
zl = oz-M> 
cz + d 
by which a certain circle in the plane of imaginary quantity 
is transformed into itself. Group Of an equation, in 
math. See equation. Group of fc dimensions, in math., 
a group whose elements have each k indices, or are arranged 
in a matrix of * dimensions. Hamilton group, in geol., 
a division of the Devonian series, as established by the 
New York geological survey. Its geological position is be- 
tween the Marcellus and the Genesee shale, and it extends 
south and west from New York over an extensive area. 
Shales and flagstones are its characteristic petrographic 
feature, and the quarries in this formation are of value 
and importance. Harlech group, in Eng. geol., the 
lowest division of the Primordial or Ctunbro-SDurian series, 
