Abbildungen der Seite
PDF
EPUB

CHIMPANSE, Simia troglodytes, about which so many fables have been related, certainly very nearly resembles man in physical organization. They reside in troops, and can walk with a cane, or use it in self-defence, with adroitness. It is considerably intelligent, and by some naturalists, is said to be susceptible of a kind of education. If, says a modern writer, there be any truth in the statements of travellers, regarding the great wild man of the forests of Africa, there is little reason to doubt that this formidable animal will turn out to be the adult chimpanse, as all the specimens brought to Europe displayed their nonage by their teeth, and other indications.

TENCH. Tinca vulgaris.—This fish, like the carp, has a thick, short body, of a brownish yellow color, and measures from twelve to fourteen inches in length. It is also very tenacious of life. In clearring out an old pond in Yorkshire, England, in 1801, where rubbish had been thrown for years, and where no fish were supposed to reside, two hundred tench and as many perch were found; and in a hole, among some roots, was also discovered a large fish, 2 feet 9 inches long, and 2 feet 3 inches in circumference, which appeared to have been stationary for years, and which, in the process of growth, had accommodated its body to the form of the hole.

PUFF-BALL. Lycoperdon.-Every particle of the extremely fine dust of the puff-ball, seen in the fields, is of a globular form, of an orange color, and also has a minute stalk on one side. After the smoke subsides, on breaking a puff-ball, the stalk of the globule settles in the ground, for that appendage is invariably the under side when at rest. So very small are the globules, that by actual examination under a microscope, it has been ascertained that a cube the diameter of a hair, would be equal to one hundred and twentyfive thousand of them. Persons have been made blind considerable time, by this mushroom smoke. Inflammation and darting pains, which result from an incautious exposure, are supposed to be caused by the sharpness of the stalks.

COLD. The greatest natural cold ascertained by thermometrical measurement, was experienced by the elder Gmelin, in 1735, at Ianiseik: the mercury froze in the instrument, and the sparrows and jays were all killed.

PHILIPPINE WEAVER, Plocus Philippinus, a native of the Philippine Islands, is a very curious bird. The plumage is brown above, and yellowish beneath-the throat, brown, and the crown of the head and breast, yellow. It forms a nest in a remarkable manner, like a long cylinder, swelling out in the middle, of fine fibres of leaves and grass, which is fastened at one end to the topmost branch of a high tree. Within are two compartments, the eggs being deposited in the globose region; and the entrance is at the bottom. Generally, the nest is suspended over water. The weaver may be rendered so very tame as to come and perch on its master's hand, or fetch and carry small parcels, like a dog.

JAVANESE BAT, Pteropus Javanicus, is the largest bat in the world, the body being a foot long, and the spread of the wings five feet in extent. In the lower parts of Java they are numerous, and live socially. Individuals select a large tree for a resort, and suspending themselves by the claw of the posterior extremity, to the branches, present a singular spectacle. They pass the greater part of the day in sleep. Soon after sunset they gradually quit their hold and proceed to the forests, villages and plantations, devouring indiscriminately every kind of fruit not protected against their depredations.

THE CIVET, Viverra civetta, which furnishes the odoriferous substance called civet, in the East, is an animal of considerable commercial importance. Civet is secreted in a bag in the posterior part of the body, which opens externally by a narrow cleft; and each sac-for there is one on either side-is about the size of an almond. Inside, the lining membrane is slightly covered with hair. When nearly full, the animal has the power of compressing them, so as to extrude the superfluous portion of the secretion.

PECULIAR GROWTH OF HUMAN HAIR.-White mentions an Italian lady whose hair trailed on the ground when she stood upright. The same may be said of the fashionahle Greek females of the present day. A Prussian soldier had it long enough to reach the ground. Mention is made by Lawrence of an English lady, whose hair was six feet long. Mr. Hearne saw an American Indian, six feet tall, whose hair, which, by the way, was only a single lock, touched the ground.

SYMPATHY.-On the authority of Pallas, a well-known writer, it is stated, that when the camel refuses to nurse her young, which is not a very common circumstance, the Mongols and the Daurian Tungooses have recourse to an expedient which is always successful. They make a plaintive noise in imitation of the calf, which elicits copious tears from the mother, whose maternal feelings are so excited, that she cannot any longer deny her helpless offspring.

FASHIONABLE EARS.-The Brazilian Indians, after slitting their ears, insert gourds, beginning with the neck, aud keep crowding in further and further, from time to time, till the lower portion actually touches the shoulders. By this contrivance, ornaments show to advantage; but when they go into battle, they are tied together behind the head to be out of the way.

:

TO CORRESPONDENTS.

An Essay on ACOUSTICS, with its numerous diagrams, has been received, and will be the leading article a few weeks hence.

A valuable paper, accompanied with illustrations, on moulding with plaster, or the art of taking masks from living faces, &c., which must be highly useful to those who cultivate natural history, as well as artists, will also appear as soon as room can be afforded.

J. S. J. has shown more revenge than is warrantable: a little larger development of the organ of benevolence would certainly contribute to his own personal happiness; and it is therefore recommended to him to cultivate its growth. We shall never consent to have any man abused, in this Journal, for what he has written; particularly, when, as in the present case, it is so clearly shown that ENVY, and nothing else, prompted the author to manufacture this scurrilous article. Deliver us from the polluting touch of that devil in the form of a human being, who, while he daily offers you his hand, in the concealed recesses of his hypocritical heart, would heartily rejoice to see you consigned to the tomb.

The communication from Craftsbury, Vt., on Rational Analysis, will be in the next number.

Mr. PAGE's paper is safe.

Mr. FOWLER will find a similar operation, with nearly the same results, in Saunder's Treatise on the Eye, page 200, London edition of 1816.

PLINY, all well.

SCIENTIFIC TRACTS

AND

FAMILY LYCEUM.

MAY 1, 1834.

[Furnished for the Scientific Tracts and Family Lyceum.]

MOULDING AND CASTING IN PLASTER.

AN attempt has been made to give, in a few words, a practical account of the manner in which casts are made, and of the moulds in which figures are cast. If the attempt has been successful, the writer will not deem the short time spent in preparing it, wasted.

As every one can see the important uses to which this art can be applied, there will be no necessity of enumerating them here. Some few, however, will be mentioned,

as the different modes in which moulds must be made and casts taken, are described.

Before proceeding to the subject, it will be well to mention the articles and apparatus used. For casting and making moulds, the following materials are used, viz., plaster of paris, or native sulphate of lime, sulphur, wax, fish-isinglass, tin-foil, and tin. The plaster is prepared by grinding the gypsum very fine, and afterwards by boiling or baking it, as required for coarse or fine casting. By this means the water of crystalization is expelled. When used, water is added to this impalpable powder, which supplies the place of that expelled, and causes it to assume again the solid form. When an extra article is required, the plaster is again passed between the stones of the mill, and sifted. The nicest will resemble the finest wheat flour. The moisture of the atmosphere will injure it, if it is exposed to its influence; therefore we must guard against

it, and every description of dampness. Plaster already prepared can be obtained at a trifling expense, in every large city. In this, there are many mills exclusively devoted to the purpose of preparing plaster for casting and stucco-work. For medallions and ornamental figures, the plaster cannot be too fine and white; for moulds, a coarser sort will answer. Figure-casters prefer for use that which does not harden soonest the reason is plain, for they are enabled to cast more figures at one mixing. For some purposes it cannot harden too quick.

Although plaster is used for casting figures and making moulds generally, nevertheless, for some purposes, the other articles mentioned are much better. Sulphur is much used for taking moulds from coins, medallions and bass-reliefs, on account of the exact and minute impression which it is capable of receiving. Tin-foil and tin are used when sulphur would injure the medals to be copied. Wax is much used for imitating fruit and flowers, and for some parts of plaster moulds where it would be difficult to use the gypsum. Isinglass and common glue likewise are used. These articles can be obtained at any of the druggists' shops.

Fig. I.

a

The utensils necessary for casting are always at hand; viz., bowls, spoons, knives, &c. For trimming casts, it would be well to have an instrument (see Fig I,) about eight inches long, the edges of which, from a to b, and from c to d around to c, are sharp; from b to c the instrument should be round, so as to fit the hand of the operator. This can be made by any smith, from a piece of steel, or from brass, which is much better, on account of its not rusting. The bowl used, should have a spout or nose, like that of a pitcher, in order to direct the material, when required, in a small stream. The other necessary things will suggest themselves.

« ZurückWeiter »