Chapter VII: DUNCAN FARQUHARSON GREGORY (1813-1844), brother of the preceding, (9)

GROUND-ICE,[1] ice formed at the bottom of streams while the temperature of the water is above freezing-point. Everything points to radiation as the prime cause of the formation of ground-ice. It is formed only under a clear sky, never in cloudy weather; it is most readily formed on dark rocks, and never under any covering such as a bridge, and rarely under surface-ice. Professor Howard T. Barnes of McGill University concludes that the radiation from a river bed in cold and clear nights goes through the water in long rays that penetrate much more easily from below upwards than the sun's heat rays from above downwards, which are mostly absorbed by the first few feet of water. On a cold clear night, therefore, the radiation from the bottom is excessive, and loosely-grown spongy masses of anchor-ice form on the bottom, which on the following bright sunny day receive just sufficient heat from the sun to detach the mass of ice, which rises to the surface with considerable force. It is probable that owing to surface tension a thin film of stationary water rests upon the boulders and sand over which a stream flows, and that this, becoming frozen owing to radiation, forms the foundation for the anchor-ice and produces a surface upon which the descending frazil-ice (see below) can lodge. The theory of radiation from the boulders is supported by the fact that as the ice is formed upon them in response to a sudden fall in the air temperature, it is only released under the influence of a strong rise of temperature during the morning. It may not rise for several days, but the advent of bright sunlight is followed by the appearance on the surface of masses of ground-ice. This ice has a spongy texture and frequently carries gravel with it when it rises. It is said that the bottom of Lake Erie is strewn with gravel that has been floated down in this way. This "anchor-ice," as it was called by Canadian trappers, frequently forms dams across narrow portions of the river where the floating masses are caught. Dr H. Landor pointed out that the Mackenzie and Mississippi rivers, which rise in the same region and flow in opposite directions, carry ground-ice from their head-waters for a considerable distance down stream, and suggested that here and in Siberia many forms of vegetable and animal life may be distributed from a centre by this agency, since the material carried by the floating ice would contain the seeds and eggs or larvae of many forms.

Besides ground-ice and anchor-ice this formation is called also bottom-ice, ground-gru and lappered ice, the two last names being Scottish. In France it is called _glace du fond_, in Germany _Grundeis_, and in French Canada _moutonne_ from the appearance of sheep at rest, since the ice formed at the bottom grows in woolly, spongy masses upon boulders or other projections.

"Frazil-ice" is a Canadian term from the French for "forge-cinders." It is surface ice formed in spicules and carried downwards in water agitated by winds or rapids. The frazil-ice may render swiftly moving water turbid with ice crystals, it may be swirled downwards and accumulated upon the ground ice, or it may be swept under the sheet of surface-ice, coating the under surface of the sheet to a thickness as great as 80 ft. of loose spicular ice.

See W. G. Thompson, in _Nature_, i. 555 (1870); H. Landor, in
_Geological Magazine_, decade II., vol. iii., p. 459 (1876); H. T.
Barnes, _Ice Formation with special Reference to Anchor-ice and
Frazil_ (1906).

FOOTNOTE:

[1] The O. Eng. word _grund_, ground, is common to Teutonic
languages, cf. Du. _grond_, Ger. _Grund_, but has no cognates outside
Teutonic. The suggestion that the origin is to be found in "grind,"
to crush small, reduce to powder, is plausible, but the primary
meaning seems to be the lowest part or bottom of anything rather than
grit, sand or gravel. The main branches in sense appear to be, first,
bottom, as of the sea or a river, cf. the use, in the plural, for
dregs; second, base or foundation, actual, as of the first or main
surface of a painting, fabric, &c., or figurative, as of a principle
or reason; third, the surface of the earth, or a particular part of
that surface.

GROUND NUT (Earth Nut, Pistache de Terre, Monkey Nut, Pea Nut, Manilla Nut), in botany, the fruit or pod of _Arachis hypogaea_ (nat. ord. Leguminosae). The plant is an annual of diffuse habit, with hairy stem, and two-paired, abruptly pinnate leaflets. The pods or legumes are stalked, oblong, cylindrical, about 1 in. in length, the thin reticulated shell containing one or two irregularly ovoid seeds. After the flower withers, the stalk of the ovary has the peculiarity of elongating and bending down, forcing the young pod underground, and thus the seeds become matured at some distance below the surface. Hence the specific and vernacular names of the plant. Originally a native of South America, it is extensively cultivated in all tropical and subtropical countries. The plant affects a light sandy soil, and is very prolific, yielding in some instances 30 to 38 bushels of nuts per acre. The pods when ripe are dug up and dried. The seeds when fresh are largely eaten in tropical countries, and in taste are almost equal to almonds; when roasted they are used as a substitute for chocolate. In America they are consumed in large quantities as the "pea-nut"; but are not much appreciated in England except by the poorer children, who know them as "monkey-nuts." By expression the seeds yield a large quantity of oil, which is used by natives for lamps, as a fish or curry oil and for medicinal purposes. The leaves form an excellent food for cattle, being very like clover.

Large quantities of seeds are imported to Europe, chiefly to Marseilles, London and Hamburg, for the sake of their contained oil. The seeds yield from 42 to 50% of oil by cold expression, but a larger quantity is obtained by heat, although of an inferior quality. The seeds being soft facilitate mechanical expression, and where bisulphide of carbon or other solvent is used, a very pure oil is obtained.

The expressed oil is limpid, of a light yellowish or straw colour, having a faint smell and bland taste; it forms an excellent substitute for olive oil, although in a slight degree more prone to rancidity than the latter. Its specific gravity is 0.916 to 0.918; it becomes turbid at 3 deg. C., concretes at +3 deg. to -4 deg. C., and hardens at +7 deg. C. It is a non-drying oil. Ground nut oil consists of (1) oleic acid (C18H34O2); (2) hypogaeic acid (C16H30O2), by some supposed to be identical with a fatty acid found in whale oil; (3) palmitic acid (C16H32O2); and (4) arachic acid (C20H40O2). The oil is used in the adulteration of gingelly oil.

GROUND-PEARL, the glassy secretion forming the pupacase of coccid insects of the genus _Margarodes_, belonging to the homopterous division of the Hemiptera.

GROUND RENT. In Roman law, ground rent (_solarium_) was an annual rent payable by the lessee of a _superficies_ or perpetual lease of building land. In English law, it appears that the term was at one time popularly used for the houses and lands out of which ground rents issue as well as for the rents themselves (cf. _Maundy_ v. _Maundy_, 2 Strange, 1020); and Lord Eldon observed in 1815 that the context in which the term occurred may materially vary its meaning (_Stewart_ v. _Alliston_, 1 Mer. 26). But at the present time the accepted meaning of ground rent is the rent at which land is let for the purpose of improvement by building, i.e. a rent charged in respect of the land only and not in respect of the buildings to be placed thereon. It thus conveys the idea of something lower than a rack rent (see RENT); and accordingly if a vendor described property as property for which he paid a "ground rent," without any further explanation of the term, a purchaser would not be obliged to accept the property if it turned out to be held at a rack rent. But while a rack rent is generally higher in amount than a ground rent, the latter is usually better secured, as it carries with it the reversionary interest in buildings and improvements put on the ground _after_ the date at which the ground rent was fixed, and accordingly ground rents have been regarded as a good investment. Trustees empowered to invest money on the security of freehold or copyhold hereditaments, may invest upon freehold ground rents reserved out of house property. In estimating the amount that may be so invested, account may be taken of the value of the houses, as, if the ground rents are not paid, the landlord can re-enter. Again, where a settlement authorizes trustees to purchase lands or hereditaments in fee-simple or possession, a purchase of freehold ground rents has been held to be proper. A devise of "ground rent" carries not only the rent but the reversion. Where a tenant is compelled, in order to protect himself in the enjoyment of the land in respect of which his rent is payable, to pay ground rent to a superior landlord (who is of course in a position to distrain on him for it), he is considered as having been authorized by his immediate landlord to apply his rent, due or accruing due, in this manner, and the payment of the ground rent will be held to be payment of the rent itself or part of it. A lodger should make any payment of this character under the Law of Distress Amendment Act 1908 (s. 3; and see RENT). Ground rents are apportionable (see APPORTIONMENT).

In Scots law, the term "ground rent" is not employed, but its place is
taken, for practical purposes, by the "ground-annual," which bears a
double meaning. (i.) At the time of the Reformation in Scotland, the
lands of the Church were parcelled out by the crown into various
lordships--the grantees being called Lords of Erection. In the 17th
century these Lords of Erection resigned their superiorities to the
crown, with the exception of the feu-duties, which were to be retained
till a price agreed upon for their redemption had been paid. This
reserved power of redemption was, however, resigned by the crown on
the eve of the Union and the feu-duties became payable in perpetuity
to the Lords of Erection as a "ground-annual." (ii.) Speculators in
building ground usually grant sub-feus to builders at a high feu-duty.
But where sub-feus are prohibited--as they might be, prior to the
Conveyancing (Scotland) Act 1874--and there is much demand for
building ground, the feuars frequently stipulate for an annual rent
from the builders rather than for a price payable at once. This annual
rent is called a "ground-annual." Interest is not due on arrears of
ground-annuals. Like other real burdens, ground-annuals may now be
freely assigned and conveyed (Conveyancing (Scotland) Act 1874, s.
30).

The term "ground rent" in the English sense does not seem to be generally used in the United States, but is applied in Pennsylvania to a kind of tenure, created by a grant in fee simple, the grantor reserving to himself and his heirs a certain rent, which is the interest of the money value of the land. These "ground rents" are real estate, and, in cases of intestacy, go to the heir. They are rent services and not rent charges--the statute _Quia Emptores_ never having been in force in Pennsylvania, and are subject to all the incidents of such rents (see RENT). The grantee of such a "ground rent" may mortgage, sell, or otherwise dispose of the grant as he pleases; and while the rent is paid the land cannot be sold or the value of the improvements lost.

A ground rent being a freehold estate, created by deed and perpetual in duration, no presumption could, at common law, arise from lapse of time, that it had been released. But now, by statute (Act of 27th of April 1855, s. 7), a presumption of release or extinguishment is created where no payment, claim or demand has been made for the rent, nor any declaration or acknowledgment of its existence made or given by the owner of the premises subject to it, for the period of 21 years. Ground rents were formerly irredeemable after a certain time. But the creation of irredeemable ground rents is now forbidden (Pennsylvania Act 7 Assembly, 22nd of April 1850).

For English Law see Foa, _Landlord and Tenant_ (3rd ed., London,
1901); Scots Law, Bell's _Principles_ (10th ed., Edinburgh, 1899);
American Law, Bouvier, _Law Dict._ (Boston and London, 1897).
(A. W. R.)

GROUNDSEL (Ger. _Kreuzkraut_; Fr. _senecon_), _Senecio vulgaris_, an annual, glabrous, or more or less woolly plant of the natural order Compositae, having a branched succulent stem 6 to 15 in. in height, pinnatifid irregularly and coarsely-toothed leaves, and small cylindrical heads of yellow tubular florets enveloped in an involucre of numerous narrow bracts; the ribbed fruit bears a soft, feathery, hoary tuft of hairs (_pappus_). The plant is indigenous to Europe, whence it has been introduced into all temperate climates. It is a troublesome weed, flowering throughout the year, and propagating itself rapidly by means of its light feathery fruits; it has its use, however, as a food for cage-birds. _Senecio Jacobaea_, ragwort, is a showy plant with heads of bright yellow flowers, common in pastures and by roadsides. The genus _Senecio_ is a very large one, widely distributed in temperate and cold climates. The British species are all herbs, but the genus also includes shrubs and even arborescent forms, which are characteristic features of the vegetation of the higher levels on the mountains of tropical Africa. Many species of the genus are handsome florists' plants. The groundsel tree, _Baccharis halimifolia_, a native of the North American sea-coast from Massachusetts southward, is a Composite shrub, attaining 6 to 12 ft. in height, and having angular branches, obovate or oblong-cuneate, somewhat scurfy leaves, and flowers larger than but similar to those of common groundsel. The long white pappus of the female plant renders it a conspicuous object in autumn. The groundsel tree has been cultivated in British gardens since 1683.

The Old English word, represented by "groundsel," appears in two
forms, _grundeswylige_ and _gundaeswelgiae_; of the first form the
accepted derivation is from _grund_, ground, and _swelgau_, to
swallow; a weed of such rapid growth would not inaptly be styled a
"ground-swallower." If the form without the r be genuine, the word
might mean "pus-absorber" (O.E. _gund_, filth, matter), with reference
to its use in poultices for abscesses and the like.

GROUND-SQUIRREL, one of the names for a group of (chiefly) North American striped terrestrial squirrel-like rodents, more generally known as chipmunks. They are closely allied to squirrels, from which they are distinguished by the possession of cheek-pouches for the storage of food. The sides, or the sides and back, are marked with light stripes bordered by dark bands; the ears are small, and without tufts; and the tail is relatively short. With the exception of one Siberian species (_Tamias asiaticus_), ground-squirrels are confined to North America, where they are represented by a large number of species and races, all referable to the genus _Tamias_. In North America ground-squirrels are migratory, and may be abundant in a district one year, and absent the next. They feed on nuts, beechmast, corn and roots, and also on grubs. With the assistance of their cheek-pouches they accumulate large supplies of food for the winter, during which season they lie dormant in holes. Although generally keeping to the ground, when hunted they take to trees, which they climb in search of food. One of the longest known American species is _T. striatus_.