Popular Science Monthly/Volume 6/January 1875/Miscellany

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MISCELLANY.

Climate of the Glacial Period.—This subject is discussed, in the October number of the Quarterly Journal of Science, by Mr. Thomas Belt. The cold of the glacial epoch, he thinks, was caused neither by elevation of the land in high latitudes, nor by the position of the earth due to the eccentricity of its orbit, as suggested by Lyell, Croll, and others; but rather by great obliquity of the ecliptic. If the axis of our globe be as that of Jupiter, the days and nights would be twelve hours each, and there would be no succession of seasons. The hot climate of the equator would become more temperate toward the poles, and no snow could accumulate at the sea-level, except, perhaps, immediately around the poles.

With beginning of obliquity of the sun's path, seasons of heat and cold would succeed each other, and these would become respectively lengthened and intensified as the obliquity increased. The long winters of intense cold would cause great accumulation of snow, which the summer could not melt. A climate is made more severe by presence of ice and snow, as many of the sun's rays of both heat and light are reflected, and the earth is not warmed by them. Thus, whatever tends to increase the area of snow increases the severity of the climate. The growth of the ice-sheet would cause it to extend toward the equator, and the movement of warm currents might be arrested. The heat of their waters, before expended in melting ice in the polar regions, would now produce great evaporation along the margin of the ice-belts, and the source of rainfall be augmented.

The great obliquity of the sun's path, contended for by Mr. Belt, exists in the planet Venus, where the tropics overlap the polar circle, and a similar state of things here would give us the glaciers as they existed in the ice-age. Moreover, a change in its obliquity back until the sun's path was over the equator, would give the climate which produced tropical plants within the polar circle. The fact of their existence demonstrates the presence there of a mild climate—as enormous unmelting glaciers prove a climate of intense and continued cold.

The cause of change in the sun's path he finds in changes in the distribution of the matter of the earth. He cites the fact of the earth's equatorial protuberance, and says the mass takes the form of an ellipse, and is not circular, as assumed by some mathematicians, and is itself a cause of change, altering the poles of rotation and the sun's path. Moreover, much may be due to former upheavals and depressions of the earth's crust. The increase of polar ice is, according to Mr. Belt, contemporaneous with increase of obliquity of the sun's path, and must diminish the difference between the earth's equatorial and polar diameters. The tendency of this would be to diminish the obliquity of the sun's path, ameliorate climate, and approximate to a uniformity of seasons and of day and night.

The coming of the cold climate, and consequent increase of polar ice, he thinks was gradual and continuous, and he finds no evidence in Scotland, or elsewhere, of interglacial periods of mild climate. Mr. Belt claims that the glaciation of the north and south poles was simultaneous, as the climate north and south of the equator must have been nearly the same.

This accumulation of ice at both poles accounts, in Mr. Belt's opinion, for several phenomena usually attributed to elevation of land. He thinks the level of the ocean must have been lowered not less than 2,000 feet to supply the ice-sheets.

In the ice once formed upon the polar regions, Mr. Belt finds a dynamic agent adequate to important geological changes. Thus their weight would cause the polar lands to sink until the earth attains its normal form; by their melting, and flowing toward the equator, the equilibrium is disturbed. But the disturbance from this cause is probably very small, "if," as Mr. Belt concludes, "the earth's interior be as cold as space, and movements occur only in its upper strata."

 

An Ornithological Land-lubber.—Toward the end of last December, the Challenger expedition visited Prince Edward's Islands, situated about 1,100 miles southeast of the Cape of Good Hope. We find in the Times the following notes concerning the habits of the albatross, a bird which frequents these islands in enormous numbers: "The whole of the wet, sodden, flat lands of Marion Island, one of the group, were studded with albatrosses, sitting on their nests. The magnificent birds, most of whom were asleep, covered the ground in such numbers that they looked like a flock of sheep scattered over a meadow. The nests were freshly covered with tufts of grass and moss, and stood some two feet above the swampy ground. It was evidently the beginning of the breeding-season, as few eggs were attainable. These splendid birds, weighing 19 ½ pounds, and measuring 10 ½ feet from tip to tip of wing, seen to such advantage while in their glory at sea, so evidently at home as they sweep gracefully through the air, are, on land, 'completely at sea.' It appears impossible for them to hover; so, on alighting at the end of a swoop, the momentum of the body continues after their feet have touched the ground, until they literally turn head-over-heels on to their backs, from which inglorious position their efforts to regain their equilibrium are any thing but graceful. While advancing to the nest, the neck is extended and the body lowered, as they waddle along, like a goose. To rise in the air, they are obliged to run, with extended wings, for some 200 yards, over the soaking grass, before they attain sufficient velocity for the air to get under their wings, and allow them to feel themselves again masters of the situation. Once landed, they are powerless to resist attack: a sharp snap of the beak is their only means of offense or defense. In taking their eggs, the readiest way is to push them backward with a stick forced against their breast, which, balanced as they were, on the edge of the raised nest, was easy work, the drop of two feet being just sufficient to send them on to their backs and prevent them rising, until after the prize was captured."

 

Decomposition of Eggs.—For some time before his death, Dr. Grace-Calvert was engaged, in company with Mr. William Thomson, in investigating the subject of the decomposition of eggs. From these researches, as now published by Mr. Thomson in the Chemical News, it appears that eggs, when the shells are intact, can only be decomposed by one, two, or all of three different agencies. The first of these agencies is the putrid cell. This may be developed in the egg, however effectually the shell is protected against spores from without, or the diffusion of gases; it is generated from the yelk. Certain gases have the effect of retarding or preventing its growth, as carbonic dioxide and coal-gas, but it is promoted by oxygen. One egg, which had for 118 days remained in an atmosphere of oxygen, was found to be decomposed entirely by "putrid cell;" the yelk had expanded, and was thoroughly mixed up with the white, and the contents emitted a putrid smell. The atmosphere, once pure oxygen, on analysis showed only a fraction of one per cent, of that gas, while the amount of carbonic dioxide was 95 per cent.

The second agency in decomposition is a vibrio, which in all cases comes from without, and never exists originally in the egg. Whole eggs that remain dry, exposed to the atmosphere for any length of time, are never attacked by this animalcule; but, if the outside of the shell becomes moist, the vibrios floating in the atmosphere fall on it and develop in the contents. The third agency is a fungus, the Penicilium glaucum, which exists suspended in the atmosphere. If whole eggs are placed in a constant draught of air, but few will be attacked by this fungus; but, if they are left in a stagnant atmosphere, the floating spores will settle on the shell, and send their long fibres through it into the contents. This fungus cannot grow in an atmosphere of carbonic dioxide, but in oxygen its growth is most luxuriant. In some cases of decomposition by the penicilium the egg was found to appear as if it had been perfectly coagulated by boiling. The filaments of the fungus branch about in immense numbers in all directions, twisting and twining into each other among the contents.

 

Experiments on the Living Human Brain.—Some experiments, made by Dr. Bartholow, of Cincinnati, on the living human brain, having drawn upon him the sharp censure of sundry professional journals, he has offered an explanation of his conduct in the British Medical Journal. "The person on whose brain the experiments were made was," he writes, "hopelessly diseased with a rodent ulcer, which had already invaded the dura mater; life could not have lasted much longer in any case. The patient herself consented to have the experiment made. The experiment consisted in applying electricity to the brain, as in Terrier's researches, and it was believed that fine insulated needles could be introduced without injury, for the following reasons: The brain has been successfully incised to discharge pus. Portions of the brain have been lost without fatal injury to the patient. Then, the faradic current was used, which has no electrolytic action. In the present case it was the ulcer, not the puncture of the needles, that caused death." Dr. Bartholow concludes his letter as follows: "Notwithstanding my sanguine expectations, based on the facts above stated, that small insulated needle-electrodes could be introduced without injury into the cerebral substance, I now know that I was mistaken. To repeat such experiments with the knowledge we now have, that injury will be done by them, would be in the highest degree criminal. I can only now express my regret that facts which I hoped would further, in some slight degree, the progress of knowledge, were obtained at the expense of some injury to the patient."

 

The Struggle for Existence.—Mr. Buckland recently fought a pitched battle in the Round Pond, Kensington Gardens, with the innumerable hosts of a crustacean parasite that was destroying the fishes. Having learned that there was something wrong at the pond, Mr. Buckland went there to make a reconnoissance, and found, at one point, some little distance from the bank, a dense "cloud of fish." Having waded into the midst of them, he discovered that the supply-pipe, through which fresh water was admitted to the pond, was nearly choked up. The fish wanted fresh water, evidently. He took up with a landing-net one or two of those that were most sickly, and found them literally covered with parasites. Various means were tried for removing the parasites, the most expeditious way being the use of a stiff brush, with sand. Having thus taken out of the pond, cleaned, and returned again to the water, many hundred fish, it was discovered that the labor was in vain, for the parasites were so numerous that soon the fishes were infested again. The crustaceans plainly were holding their own. Mr. Buckland now cleared away the mud in front of the pipe, so that the fish might have a chance of rubbing off their tormentors against the bottom. He next conceived the idea of spreading a quantity of gravel about the pipe. With the aid of this and an abundant supply of fresh water at a low temperature, the fish were enabled to rid themselves of their parasites easily, and, in the cooler water, the latter did not find the conditions of life so favorable.

 

A Worm that the Sparrows refuse. — We recently noted the appearance in the public parks and squares of Philadelphia of a caterpillar which threatened to destroy the trees. The English sparrow had effectually exterminated the measuring worm in those parks, but showed no disposition to attack this new destroyer of the foliage. At the late meeting of the American Association, Dr. John L. Le Conte described this insect as the larva of the moth Orgyia leucostigma. It is a slender caterpillar, covered with stiff yellow-and-black hairs. The sparrow does not attack it, being deterred, probably, by the bristles, by which it is protected. But, fortunately, the nuisance can be abated without the aid of the sparrows. When the caterpillar has attained its full growth on the tree, it crawls to a neighboring wall or fence, and there, fixing its cocoon, undergoes transformation. The remedy against the annoyance is now very simple, viz., by sweeping the cocoons from the walls and fences with stiff brushes, and placing around the trees rings of tin-plate inclined at an angle. This will give the trees immunity, because the insects are not provided with wings for flight.

 

A New Source of Illuminating Gas. — An oil-bearing shale of considerable thickness, called Kimmeridge coal, or clay, underlies the whole county of Dorset, and is met with in other parts of England. Various attempts have been made to utilize this deposit for the purpose of producing light and heat, but with little success hitherto. Now, however, the Rev. Henry Moule has succeeded in devising a method of producing from it a good, useful gas. The new gas is obtained by the destructive distillation of the shale, the gaseous products being submitted to purification before use. In this latter process, as also at other stages of the manufacture, chalk is used. The gas itself, though not odorless, is by no means so pungent nor so unpleasant as ordinary coal-gas. During combustion no odor is perceptible, and, so far as can at present be ascertained, the products of combustion contain no noxious gases. Besides the gas, a pungent oil is produced, which Mr. Moule believes can be rendered comparatively odorless, and may with advantage be applied to various purposes. The inventor also proposes to utilize the heat-giving properties of shale and chalk for heating, both by means of gas and in a direct manner, his plans having been matured in this respect.

 

Contagious Ophthalmia. — In English poor-houses and "pauper-schools," contagious ophthalmia has, from the foundation of such institutions, afflicted the inmates. It is produced by unsanitary conditions of life — want of cleanliness, overcrowding, ill-ventilation, etc. It might be supposed that these establishments would have been greatly improved in later times, owing to the increased attention now bestowed on public hygiene; but the contrary is the fact, as we learn from a discourse by Dr. Brudenell Carter. A serious charge is brought by this gentleman against the Poor-Law Board, viz., that during the last few years their unwisdom has developed this malady in workhouses and pauper schools "in a manner to which previous English experience affords no parallel." The Government has refused to let the truth be seen, but Dr. Carter has been able to obtain, from a private source, a copy of a report made to an official inspector by the medical officer of one of the schools. It states, among other curious matters, that, of 1,062 children in the school in question, only 182 had escaped ophthalmia; 163 had suffered from one attack of the disease, 151 from two attacks, HO from three, 75 from four, 54 from five, 58 from six, 22 from seven, 25 from eight, 7 from nine, 11 from ten, and 204 from more than ten attacks. In a considerable proportion of these cases sight would eventually be greatly impaired, and in many it would be wholly lost.

 

Portuguese Agriculture.—The art of agriculture is in a very primitive state in Portugal, the instruments of husbandry employed being very little different from those in use during Roman times. Two kinds of ploughs are used, both very rude. The harrow, too, is of the rudest construction, having 15 to 20 teeth of iron or wood, set quincunx fashion into a strong, oblong square wooden frame, with one cross-bar. As a substitute for the roller, the harrow can be reversed, loaded with stones, and drawn sledge-wise over the land. The hoe is indispensable in Portuguese field-husbandry; ground can be prepared by it for seeds, or for planting, more quickly than it can be dug by a spade, though it is less completely stirred and turned over. The cart has two low wheels of solid wood, with iron tires, fixed immovably to an axle which revolves with them. The yoke is fixed to the necks of the oxen, or, in some localities, to the horns.

 

Lightning among a Flock of Geese.—A singular occurrence, which took place on March 16th, in the northern part of Sutter and the southern part of Butte Counties, Cal., is narrated as follows in the Sutter Banner: "On that day, just before sunset, a large thunder-cloud came up, apparently from the northeast, accompanied by an unusual amount of chain-lightning. First a small amount of hail fell, and then followed sufficient snow to whiten the ground. As the hail began to fall, and the lightning flashed, thousands of wild-geese, which were in the ponds of shallow water which exist in that locality during very wet winters, suddenly rose up in a great flutter, as if many hunters had discharged a volley among them. They went up and up, apparently to rise above the fearful cloud. It was nearly dark, and those who saw them rise thought no more of it until morning, when they began to find dead geese, and hear of hundreds being picked up by the neighbors. Some 700 were found. One man picked up on his farm all that two horses could haul. Their heads were badly torn, and their bills split into fragments. The portion of the country thus affected was about a mile and a half wide, and reached several miles into Butte County. The terrific lightning in this cloud was witnessed by people on the Honcut, in Yuba County, and in the central portion of Sutter. The thunder was heard at the distance of twenty miles."

 

Artificial Furs.—A new method of treating fur has been patented in England, by Mr. Joseph Tussaud, one of the proprietors of the well-known wax-work establishment founded by Madame Tussaud. Mr. Tussaud removes the hair or fur from the skin, substituting for the latter an artificial skin. First, the piece of fur to be treated is soaked in lime-water, for the purpose of loosening the hair. Then it is washed in water, and hung up to dry. Next, it is laid on a board, with the hair-side up, and a solution of glue applied, care being taken not to disturb the natural position of the hairs. The glue having dried and become hard, holds the hairs so firmly as to allow the natural skin to be pulled off. An artificial skin is now applied to the roots of the hairs, by pouring over them liquid India-rubber, boiled drying-oils, or other waterproof substances, which, on drying, will form a continuous membrane supporting the hairs. The glue is then removed by steeping the fur in warm water. Furs prepared in this way are moth-proof, and superior to the natural skin for many purposes, such as mats, rugs, etc. After the removal of the hair, or fur, the skins are still available for the manufacture of leather.

 

Siamese Medicine.—A Siamese manual of medicine contains the following recipe for a poultice to cure snake-bite: "Take the eyes of vultures, crows, and cats, together with three sorts of animal deposits found on trees; mix all these together, then place nine wax-candles on as many floats made of plantain-stalks, each ornamented with flowers. After this, let the doctor make an offering of nine silver coins, nine handfuls of rice, nine ceri-leaves, and nine betel-nuts, placing a set of each on the several floats, in honor of the teacher of medicine. Then he is to launch the floats into the river, mould his paste composition into slugs, gild the slugs, and apply them to the wound." Another way of treating snakebites is the use of enchantments for calling the snake which gave the wound to suck the poison out. "For this purpose, fill three bottles with proof-spirits, then let the doctor repeat the form of incantation, drinking one of the bottles of spirits up, while he enchants over it. If the snake does not come, the doctor is to drink a second bottle, proceeding in the same way; and if, on consuming the third bottle, the serpent still declines to appear, the patient must die. But, should the snake present himself, let the doctor take three cowries in his hand, and seven times rehearse a set form of incantation till he has charmed the snake to come to his left side. Then the poison is to be brushed from the wound with a handful of meyon-leaves seven times, and the patient, if he can be got to eat a betel, will recover." Civilized practice, it may be observed, does not stop with three bottles of spirits, but continues the drinking till the snakes appear!

 

Fossil Remains of the Moa.—According to the Melbourne Argus, a number of bones of the moa have been discovered near Hamilton, New Zealand. The moa has never been seen alive since about the year 1650. Tradition describes it as a stupid, fat, indolent bird, living in forests and mountain-fastnesses, and feeding on vegetable food. The moa seems to have been extirpated for the sake of its flesh, feathers, and bones. The natives used the bones for making fish-hooks, and the skull was employed as a receptacle for holding tattooing-powder. Captain Hutton, the provincial geologist, has lately visited the locality where the bones were discovered, and ascertained from personal observation that an accumulation of these bones exists, in a tolerable state of preservation, in a swamp about a mile and a half east of Hamilton. Mixed with the moa-bones were found skeletons of the aptornis, a large bird, resembling a swan. There are also the bones of some smaller birds, and these will prove of peculiar value, as hitherto paleontological research has not offered much information as to the kind of small birds which were contemporaneous with the moa. It is estimated that about five or six wagon-loads of bones lie in the swamp at Hamilton.

 

The Pitcher-Plant.—In a paper read at the American Association, Prof. C. V. Riley gives the following description of the pitcher-plant (Sarracenia): The leaf of this plant is a trumpet-shaped tube, with an arched lid, covering more or less completely the mouth. The inside is furnished with a perfect chevaux-de-frise of retrorse bristles, commencing suddenly about an inch from the base; thence decreasing in size until, about the middle to the mouth, they are so short, dense, and compact, as to form a decurved pubescence, which is perfectly smooth and velvety to the touch, especially as the finger passes downward. Running up the front of the trumpet is a broad wing, with a hardened border, parting at the top and extending around the rim of the pitcher. Along this border, but especially for a short distance within the mouth, and less conspicuously within the lid, there exude drops of a sweetened, viscid fluid, which, as the leaf matures, is replaced by a white, papery, tasteless sediment, or efflorescence, while at the smooth bottom of the pitcher is a limpid fluid, possessing toxic qualities. The insects which perish in this liquid are numerous, and of all orders, but ants are the principal victims. The plant, however, is omnivorous as regards insects, and Prof. Riley has found in the fluid, at the bottom of the pitcher, katydids, locusts, crickets, cockroaches, flies, moths, and even butterflies, in a more or less recognizable condition.

 

Effects of the Glacial Epoch on the Distribution of Insects.—In a paper entitled "On Allied Species of Noctuidæ inhabiting Europe and America," Buffalo, October, 1874, Mr. Grote says: "For the origin of certain species we shall have to go backward to the Pleistocene, and consider the identical species as belonging to a former Arctogæal fauna. The action of the steady increase of cold which characterized the gradual inauguration of the Ice period would have been to drive the insects southward and mix the Arctogæal with the then existing 'indigenous' southern species. The summers of the middle Glacial epoch probably afforded no opportunity for the existence of Noctuidæ throughout the Northern States. On the decline of the Glacial epoch, and with a steady increase of warmth (still continuing), the species would progress northward again. We may regard such a species as Fidonia fimitaria G. & R., found in Texas, as an outlying colony of F. fasciolaria forced southward and retained by local influences, and possibly having submitted to the modification which enables us at this day to separate the two forms. During the Pliocene, the common ancestor of the two forms may have been different from either. During the Pleistocene, Holocene, and Recent periods, we must consider such species as Hadena arctica to have preserved their identity, while many may have perished or submitted to modifications, and these latter may be represented by the closely-allied species of the two faunæ. The Glacial epoch may then supersede the "Atlantis" of those entomologists who looked for a geographical connection in former times to account for the existence of identical or representative species on the two continents."

 

The Pottery of the Mound-Builders.—Prof. E. T. Cox, having examined a great many specimens of potteries of the ancient mound-builders in the Western States, has never been able to find any evidence of their having been hardened by fire, or even sun-baked. The material employed is a mixture of river-mud and, most generally, pulverized mussel-shells, united in such proportions as to make a cement which hardens in the air, or on being exposed to moisture, like the concrete of the ancient Romans; hence this ancient "pottery" is in fact a sort of artificial stone. In chemical composition it agrees very closely with the concrete made of ordinary cement-stones. These facts lead to the conclusion that the art of manufacturing concrete, or artificial stone, did not originate solely with the ancient Romans, but that it was alike understood by the earliest inhabitants of America. As regards the mechanical processes followed by these ancient artisans, Prof. Cox says: "Though it is my opinion that the so-called pottery of the mound builders was fashioned by hand, without the use of a lathe, yet I am convinced that the ancient pottery of Peru, and other South American states, was largely made of pieces formed by pressing the cement into moulds, and these pieces were subsequently united together to form the entire vessel. The lines of union are usually covered by a band, or some grotesque image. The numerous tubercles and other raised ornaments, which cover the surfaces of jugs, vases, etc., could only have been formed in this way. I do not, however, find any pottery of the mound-builders that would lead to the belief that their skill went so far as to enable them to mould it in parts, or to fashion it in any other way than by the hands."

 

A Primitive Fort.—One of the most remarkable works left by the mound-builders is a stone fort in Clarke County, Indiana. As described by Prof. E. T. Cox, this fort stands upon the terminal point of a high ridge, which is washed on its south side by the Ohio River, and on the north by Fourteen-Mile Creek. The point of the ridge is pear-shaped, and the fortification includes from eight to ten acres. The highest point at the stem of the pear is 280 feet above the Ohio, and is only 10 to 20 feet broad, presenting almost a perpendicular wall to the river. A natural wall of Niagara limestone furnishes complete protection against the approach of an enemy at the upper part of the fort, with the exception of a short gap on the creek-side, extending from the upper point southward for about 100 paces. This break in the natural wall is protected by an artificial wall 75 feet in height, made by laying up loose stone, mason-fashion, but without mortar. The base, for 65 feet in height, follows the slope of the hill-side, and then rises 10 feet vertically. Around the southern terminus of the point there is an artificial stone-wall 10 feet high, which connects the two natural walls of Niagara limestone, thus forming a complete barrier against attack. Inside the wall of masonry are numerous mounds of earth, and within the line of these mounds is a ditch 4 feet deep and 20 feet wide.

 

A Cheap Substitute for Bells.—Mr. J. A. Judson, C. E., writes us from Dutch Island, near Newport, that for several years past he has used a steel bar in place of a bell, with very satisfactory results. He caused a bar of steel about one inch and a half in diameter to be forged into an equilateral triangle of about three feet on a side, without uniting the two ends, thus forming an instrument similar in all respects except size to the rude musical appliance called the "triangle," used by negro minstrels and sometimes in brass bands. This is suspended from one of its angles by a rope attached to a simple wooden frame, and is struck by hand with an ordinary steel-faced blacksmith's hammer. A cord attached to the triangle and held in the left hand of the ringer prevents its whirling about when struck. If necessary, it may be permanently lashed, without materially interfering with the vibrations, and could then be rung by some stationary mechanical device. "I may have been fortunate," says Mr. Judson, "in finding an especially suitable bar of steel for the purpose, for it is certainly sonorous and powerful, answering all the purposes of an ordinary factory-bell, at merely the cost of so many pounds of steel, and a few hours of skilled labor."

 

Heat as a Disinfectant.—In the course of some experiments, made with a view to ascertain how far heat may be employed as a means of disinfecting articles of clothing, Dr. Ransom, of Nottingham, found that white wool, cotton, linen, silk and paper, may be heated to 250° Fahr. for three hours without apparent injury, although the wool shows a faint change of color, especially when new. The same may be said of dyed wools and printed cottons, and most dyed silks; but one kind of dyed silk easily turns brown by this heat, and pink silks of some kinds are also faded by it. The same temperature will, if continued for a longer period, slightly change the color of white wool, cotton, silk, paper, and unbleached linen, but will not otherwise injure them. A heat of 295°, continued about three hours, more decidedly singes white wool, and less so unbleached and white cotton and white silk, white paper, and linen both unbleached and white, but does not materially injure their appearance. The same heat, continued for about five hours, singes and injures the appearance of white wool and cotton, unbleached linen, white silk and paper, some colored fabrics of wool, or mixed wool and cotton, or mixed wool and silk. It is noteworthy that the singeing of any fabric depends not alone on the heat used, but also on the time during which it is exposed. In the experiment, the heat was obtained by burning gas with smokeless flame, and conducting the products of combustion, mixed with the heated air, by means of a short horizontal flue, into a cubical chamber through an aperture in its floor, and out of it by a smaller aperture in its roof. Fixed thermometers showed the temperature of the entering and outgoing currents, which represented the maximum and minimum temperatures of the chamber. A self-acting mercurial regulator maintained the temperature of the entering current at any required degree.

 

The Science of Education.—One of the most important papers read in the Section of Economic Science of the British Association was that by Mrs. Grey on the "Science of Education." The author complained that in Britain there is no adequate or general conception of what education is, and therefore of the magnitude and complexity of the facts on which a science of education, which can never be an exact, but only a mixed and applied science, must be based. We start with a confusion of terms, using education as synonymous with instruction; and the confusion of thought indicated by this misnomer runs through our whole treatment of the subject, theoretical and practical, and is shown in every discussion of the subject. It is surely time that this confusion should be replaced by a scientific conception of the process which should result in the most valuable of all products human beings developed to the full extent of their natural capacity. What is wanted is, that teachers, like practical navigators, should be furnished with the principles of a science they have not had to discover for themselves, and with charts to guide their general course, leaving to their individual acumen the adaptations and modifications required by special circumstances. We have such knowledge to guide us in improving our breeds of cattle and our crops: must we remain without it in the infinitely more important business of improving our human crop, of getting out of our human soil all that it can be made to yield for social and individual good? Must every tyro still be allowed to try experiments, not in corpore vili, but on the most delicate and precious of materials—the human body and mind, on the most powerful of all forces—human passions and the human will; experiments in which success or failure means virtue or vice, happiness or misery, lives worthy or unworthy, sowing with every action a seed of good or ill, to reproduce itself in an endless series beyond all human ken?