falls of its own weight when the pipe is empty; the pressure of balance the bucket of water; a man then alternately raises and the water, however, closes it. Weights are now placed on the lowers it by pulling the rope. Much of the land in Egypt is upper end of the spindle, so that when the pipes are full of irrigated by this contrivance, which is known as the Shadoof. water pressing upwards, the valve only just opens from its The common windlass is used instead of this where the water weight. Another opening is made in the pipe at F, communi- has to be raised from a great depth; as, however, there are a cating with a large reservoir, A, from the upper part of which large number of machines in use, it will be best to make a issues the pipe B, by which the water is to be raised. The simple division of them, and perhaps the simplest we can make upper part of this reservoir is filled with air, and a small valve, is the following:not shown in the figure, is so placed as to allow a small additional quantity to enter from time to time, and replace that carried away by the water, which under pressure absorbs a small amount of it. The opening between the pipe A B and the reservoir is closed by the valve F, which rises by the inward pressure of the water, and is closed by its own weight. We will now suppose the machine to be set in action. The weight on the valve at c being more than sufficient to overcome Fig. 30. the pressure of the water, the valve opens, and the water escapes and runs to waste. That in the pipe, however, acquires immediately a small amount of momentum, which enables it to raise the valve, and thus close the opening. The momentum thus acquired by the water cannot be instantaneously destroyed, and would burst open the end of the pipe were it not for the valve at F. This provides an escape, and the water opens it, and causes a certain amount to enter the reservoir, compressing the air contained in it, and thereby forcing a fresh amount of water up the tube B. The compressed air, however, acts as a spring, and thus the momentum of the column of water is soon destroyed; F then closes of its own weight, and the water in the tube being now at rest, c again opens and allows the water to escape as at first. When the weight at c is carefully adjusted, this opening and closing succeed one another rapidly, producing a series of stoppages, by each of which a small quantity of water is raised in the pipe B. A larger amount, however, escapes at c than ascends in B, and the amount raised diminishes, of course, with the height to which it is raised; still it is calculated that about 60 per cent. of the power of the water may be utilised by the arrangement, which certainly by its ingenuity reflects great credit on the inventor. Occasionally, in mines, a stream of water is caused to move an engine, constructed on exactly the same principle as the steam-engine, the motive power being the pressure of the water instead of the pressure of steam. By an arrangement of valves the water is made to press alternately on the upper and lower sides of the piston, and the motion thus produced is by means of a crank and fly-wheel communicated to the machinery. We have thus noticed all the most important machines designed to derive motion from a fall of water, and now pass on to the second class, or those which are intended to raise water to any required elevation. Water is one of the prime necessaries of life, and as its tendency is always to sink to the lowest level, various plans of raising it have been tried from the very earliest ages. The most primitive is by means of a bucket fastened to a rope; after a time, it was found more convenient, when the height to which the water had to be raised was not great, to fix this rope to one end of a lever supported near the middle on crossed poles, and pull by means of a rope fastened to the other and shorter end. A further improvement on this, which is at the present day much used on the banks of the Nile, consisted in fixing a weight at the other end of the lever, so as nearly to : 1. Those which act mechanically; 2. Those which act by the pressure of the air; 3. Those which act by centrifugal force. The second of these divisions contains the common pump and similar machines, which, strictly, ought not to be explained till we come to treat of pneumatics, as they involve principles which have not yet been explained; but it is best to consider all together, as in this way we can better understand their differences in construction. First, then, we notice those which act mechanically. The plan of raising water by means of a single bucket would naturally suggest the idea of fixing several, one below the other, and thus an endless chain of buckets passing over a wheel at the top was constructed. The buckets are brought up full, and when they reach the wheel strike against a support, and, being turned over, discharge their contents into a channel prepared to receive them. The wheel in this case may be turned by the foot, as is frequently done, or the power of animals may be employed. The next modification of this arrangement is what is known as the Persian Wheel, which is represented in Fig. 31. Floats are fixed to one side of an undershot or tidal wheel, and in the other side of the rim are fixed a number of pegs, from which buckets are suspended. As the wheel is turned by the force of the current, these successively dip into the water, and are brought up nearly full. The weight of their contents keeps them in a vertical position till they reach the top, where they strike against a trough, and thus are emptied into it. The water is conveyed from this by a channel not shown in the figure. By this plan the water cannot well be lifted to any great height, as the diameter of the wheel must be greater than the height. This machine can be used in a tidal river, as it will work in either direction. A further supply of water is, in this wheel, raised to the level of the axis on a totally different principle. The spokes of the wheel, instead of being made straight, as in the case of ordinary wheels, are hollow and curve considerably. Openings will be perceived on the rim, by which the water enters when they are immersed, and from the shape of the spokes it cannot flow out again, since the openings are higher than the bends. The water, therefore, travels along them towards the axis, and there is discharged into a trough prepared for it. NATURAL HISTORY OF COMMERCE. CHAPTER XI. (continued). THE NEW WORLD: NORTH, CENTRAL, AND SOUTH Climate and Soil-Temperatures of Old and New World compared Raw Produce, Animal, Vegetable, and Mineral. Animal Produce.-The indigenous fauna of America is more limited than that of the Old World, and especially so in the larger species of animals. Besides being few in number, and small in size, the animals are mostly of peculiar structure. The llama was the only domestic animal found upon the continent by the first European settlers. In the northern regions, where America all but meets the Old World in the narrow breadth of Behring's Straits, the reindeer, the elk, the bear, the fox, the beaver, and the marten are common to both hemispheres. Hunting and trapping the fur animals has been hitherto the almost exclusive vocation of the sparse population of the Hudson's Bay territories. The marine mammals-the seal, the walrus, and the whale, whose chase provides us with skins, oil, whalebone, and ivory are identical with those throughout the Arctic and sub-Arctic zones. Further south, the American bison or buffalo, hunted for its tongue chiefly, overruns Canada and the United States, herding in the prairies and savannas of the Mississippi rivers, where likewise deer are extremely numerous. Great flocks of the large-horned or wild mountain sheep live among the Rocky Mountains. Many of the quadrupeds of Mexico are peculiar to the country, but none of them are of any important economic value. ⚫ Birds are numerous and of many varieties. America is the native home of the turkey, two or three species of which are found in the forests of North and Central America. Tropical America has the curassow, a bird equally large, and as delicate of flesh. The other birds of use for food, or for industrial purposes, are closely related to those of the Old World. The Arctic shores are covered with sea-fowl as in Europe. The eagle and the vulture live in the mountains. Passenger pigeons darken the sky by the immensity of their numbers. The nandu, of La Plata, and the rhea, a smaller bird of Patagonia, represent in America the ostrich, by which name, too, they are sometimes called. Many of the American birds are valued only for the brilliancy of their colours. The delicate humming-bird ranges from Alaska southwards to Cape Horn. Beautiful parrots likewise have a large southerly range, though not ascending more than a few degrees beyond the Tropic of Cancer. Amongst the American reptiles, several are turned to useful account. Turtles abound in the enclosed seas of Central America, and upon the shores of the West Indian islands, affording one of the choicest forms of animal food; and along the Pacific coast the tortoise supplies the beautiful substance called tortoiseshell. An extraordinary fish-like reptile, caught only in the Mexican lakes, and called the axolotl, is eaten as an exceeding delicacy. whence we still get supplies, though small in comparison with the produce of the warm parts of Europe. Bees introduced from Europe, in return, supply large stores of honey. It is not the native animal produce, but the produce of animals introduced by Europeans, that distinguishes America in the present day. The domestic varieties of Europe have found the conditions of increase so favourable, that horses, cattle, and swine have returned to a state of nature, and swarm over the boundless plains, or through the forests both of the North and the South. The Indians of the North, who have become fearless riders, hunt the bison on horseback. In Mexico and Central America, the mule is used as a beast of burden. The numbers of this sure-footed animal--a compromise between the beautiful Spanish wild ass and the horse— it is hardly possible to estimate. With the knowledge of these resources, we are able to name the animal produce, of which America will have a surplus for interchange. From our own possessions and the United States, cheese and provisions as exports increase in quality and quantity every year. Hides, tallow, and wool are also exported. Furs from the extreme north, and fish both dried and pickled, to which we may add the produce of the whale fishery, are, and will remain, constituents of the grand commerce of North America. South America, less advanced, sends us chinchilla furs from Venezuela, and hides, tallow, horsehair, horns, bones, and wool from the animals that bound over the country between the llanos of the Orinoco and the shingly steppes of Patagonia. Means are being taken to export the flesh of the oxen in a fresh state to Europe, but the success as yet has been very partial. Vegetable Produce. The flora of a continent whose distinguishing physical features are vast lowlands, in temperate and tropical regions, amidst heat and moisture, may be determined beforehand as diversified and exuberant. In tropical America, vegetation reaches its utmost limits of luxu riance. Nevertheless, before the introduction of plants from Europe, the productions of the continent were peculiar, and comparatively few of them known to be useful to man. As in the case of animals, America has given little and received much. The plants introduced have spread widely, and furnished limitless stores of food. Nearly all the economic plants of Europe are now grown in the cleared parts of the United States, and the tropical zone has been enriched with many plants from corresponding parts of Africa and Asia. Indigenous Produce.-Maize is the only native representative of the cerealia; and manioc, from which cassava bread and tapioca are prepared, takes the place in South America that rice assumes in India. Allspice is the only native pungent condiment, and is akin to the various spices of India. Cocoa, and maté or Paraguay tea, are the beverages of South America, in lieu of coffee and tea. Plantains are the characteristic fruit, closely resembling the bananas of Asia. Cinchona, or Jesuit's bark-from which the invaluable drug quinine is extracted the ipecacuanha of Brazil, and the jalap of Mexico, have no representatives elsewhere. The most remarkable native products are, without doubt, first, the potato-spread from Chili throughout the world; secondly, tobacco-now grown in several countries, but brought to perfection only in its native soil of Cuba, Of minor food-products from the animal kingdom, whose capital, Havannah, gives the name descriptive oysters are so plentiful, that dinner in the United States of the best leaf. Although the indigenous plants used is never complete without them in one or more fashions for food are few, compensation is given in the weight of cooking. Oyster banks, along the low mangrove of their produce. In Europe, large spaces are covered swamps of the Southern States, form natural embank- with food-grasses and other plants, for the sustenance ments against the sea. Along the shores of California, of the inhabitants. In America, small tracts of maize, pearl oysters are found. In the class of insects, the manioc, and plantain will produce enough food for cochineal is indigenous, and was brought from Mexico, large numbers of people. As a consequence, in South 118 — N. E. Food fishes are abundant, both marine and of the river species. Exhaustless shoals of cod feed on the banks east of Cape Breton and of Newfoundland. Varieties of the herring also fill the inlets, and are caught in myriads. America, where these plants flourish, the country re mains in its wild natural state, even in the vicinity of large towns; the inhabitants not being obliged to extend their cultivation. The vigorous races of North America, however, cultivate wheat, barley, and oats, and the tropical rice, all of which, in their respective zones, flourish abundantly. Bread-fruit has been introduced, and pine-apples have become so plentiful that they grow in the fields in the West Indies as turnips do with us; and many shiploads reach our markets in the season at so moderate a cost as to bring this chief among choice fruits within reach of the poor. Coffee and sugar have proved their adaptation to the American tropics, the crops of both being enormous. The East Indian spices also grow in the West Indian islands, although not in the same perfection. Cotton has found the foreign conditions of growth in America superior to those of its native soil, and its spread is almost beyond belief. The American crops transcend all those of the rest of the earth. Besides these vegetable products that appertain to food and clothing, America possesses peculiar forest growths. At the head of these we must place the mahogany tree, the beautiful colour and grain of which, as well as its durability, placed it on its discovery highest amongst cabinet timber. Logwood, Campeachy, and Nicaragua woods are examples of American valuable dye-woods. The tendency to efflorescence in the trees of America, and the floral beauty of many of the shrubs and animals, have encouraged their diffusion through Europe. Our gardens owe to this source the grand flowering rhododendron and the magnolia. The American aloe and the cactus have found a congenial region round the Mediterranean, where they exhibit all their native vigour. The dahlia, fuchsia, nasturtium, and passion-flower, all had a Western origin. Many other trees and plants, valued for their foliage or beauty of development, from the colder parts of America, where flowers are less profuse, adorn the parks and pleasure-grounds of Europe. Vegetable Produce according to the Floral Zones. Our previous knowledge of the zones, as applied to the Old World, combined with the general knowledge gained of the produce of the New World, prepares us for a brief description of this division of the subject. The boreal region, or climate of mosses and berries, is like that of Lapland. The arborescent forms, at the extreme limit of the zone, are a few stunted birches, willows, and junipers; otherwise the ground is covered with a thick growth of lichen and moss, which defies the cold and overpowers other vegetation. Towards the southern border extensive forests, which extend into the next climatic zone, characterise the country. The region of European grains and forest trees is bounded southwards by the line of vine culture and the growth of maize. Canada and the northern United States are included within it. Peculiar species of oak, beech, and numerous other forest trees, orchard fruits and nuts, the cereals, and in the south maize, the common fibres, and, to some extent, tobacco, all flourish in this zone; woods of great value and beauty, the bird's eye maple and the mast pine being the chief varieties noted for the delicacy of their grain and texture. A peculiarity of the North American forests is, that one description of tree prevails on each variety of soil, evidence of which is given in the descriptive names of oak lands, chestnut lands, pine barrens, and cypress swamps. The sugar maple supplies from its sap most of the sugar used in Canada, and much of that used in the United States, and its produce might be indefinitely increased. Potash, principally from the beech, pitch, tar, rosin, and turpentine are forest products, in quantities corresponding with the endless sources of supply, but identical with those of Europe. Trenching on the warmer regions, the myrtle wax-tree, a kind of laurel, abounds, and supplies in its nuts a dry and brittle wax, of excellent quality and large amount. The region of wheat and tropical grains is productive also of maize and rice, the vine, citron, and melon, as in the Old World; but in reference solely to America, perhaps cotton and tobacco would be more descriptive of the zone. The mountains of Mexico separating that country from the rest of the region, and placing it on a table land raised 7,000 to 9,000 feet high, in parts, give it a flora ресиliarly its own, the botanical centre of the cochinealcactus and other plants. On the east the Alleghanies separate the fertile valley of the Mississippi from the poorer soil and barren swamps lying between these mountains and the Atlantic shores. The true tropical parts of America comprehend the central states, that is Mexico, the republics of Central America, and two-thirds of the southern continent. All the useful food plants of India are diffused throughout this zone, besides a rich vegetation of its own. Tropical grains and manioc, ginger and other spices, coffee, sugarcane, and sweet fruits, gourds and pine-apples, cocoanut and other palms, bamboos and tree-ferns, tobacco, drugs, dyes, and timber are amongst the contributions that Central America offers for man's service. Tropical South America adds other gifts. The palms are in great variety. Besides the cocoa-palm there are the cabbage, the fan, and the oil-palms, the coquilla and the vegetable ivory. Bread-fruit trees, and cow-trees producing milk, are numerous; and from allied plants, characterised by their milky juices (Euphorbiaceae), our chief supplies of caoutchouc are procured. Other products of an important nature, such as the cacao, indigenous to the country, have already been mentioned. The flora of the Andes ranges vertically through every climatic zone, beginning with the plantains and palms at their tcrrid base, and passing through the intermediate phase of climate, to the silent and frozen mountain summits, devoid of life. South of the Tropic of Capricorn the products of the torrid and temperate zones interfuse. No rice is seen, but maize grows with wheat and barley, and palms and the mulberry flourish together; tobacco, hemp, and flax ripen by the side of the melon, the lime, and the olive. Chili produces a surplus of wheat for exportation to Great Britain and other countries. Brazil is in many parts still covered with forests almost impenetrable. From them mahogany, rosewood, and various dye-woods are obtained. Beyond 40° south latitude there is little cultivation, and vegetation diminishes rapidly. The climate would admit of grain being grown, but, except in a few parts, the soil is a shingly desert upon which little will grow that can be turned to any economic use. The peninsula tapers to a point which trends southwards to the latitude of 55°, and the last ten degrees are utterly cold and desolate. LESSONS IN FRENCH.-LXXI. § 65. THE PARTICIPLE. (1.) THE participle is so called, because it participates of the nature both of the verb and of the adjective. It partakes of the nature of the verb, in having its signification and an object, and of the nature of the adjective in qualifying, like the latter, nouns and pronouns. (2.) There are two sorts of participles; the present and the past. § 66 (1). THE PARTICIPLE PRESENT. (1.) The participle present, which denotes continuance of action, answers to the English participle in ing. doucement, softly; sagement, wisely, etc. premièrement, first; d'abord, at first; ensuite, afterwards, etc. ici, here; où, where; là, there; ailleurs, elsewhere, etc. hier, yesterday; aujourd'hui, to-day; demain, to-morrow, etc. peu, little; trop, too much; beaucoup, much, many, etc. plus, more; moins, less; autant, as much, as many, etc. oui, yes; certes, certainly; comment, how; non, no; nullement, by no means; peut-être, perhaps; ne, pas, point, not, etc. bien, well; très, fort, very; tant, so much, etc. (6.) The following adverbs require an acute accent over the e preceding ment, which e is mute in the adjective: aveuglément, commodément, communément, conformément, confusément, diffusément, blindly. commodiously. commonly. importunément, importunately. incommodément, incommodi conformably. obscurément, ously. obscurely. confusedly. opiniâtrément, obstinately. (7.) Gentil, pretty, forms its adverb by dropping its final 1 and adding ment: gentiment. § 70.-DEGREES OF SIGNIFICATION IN ADVERBS ENDING IN MENT. (1.) Adverbs ending in ment are, like the adjectives from which they are formed, susceptible of three degrees of signification: the positive, the comparative, and the superlative. (2.) The first expresses the manner simply. (1.) The preposition is an invariable word which expresses the relations of words to each other. (2.) The preposition and the word which it governs form what is called indirect object. (3.) Prepositions consisting of one word, such as de, â, pour, are called simple prepositions; those consisting of several words, such as vis-à-vis, are called compound prepositions. (4.) The prepositions which may precede a verb require it to be in the present or past of the infinitive, except en, however, which requires the verb following it to be in the present participle: PAINTING IN WATER COLOURS.-I. INTRODUCTION COLOURS -BRUSHES PAPER FLAT TINTING. In commencing these instructions in water-colour painting, we shall have very little to say about the rules and practice of drawing beyond that which especially relates to our subject, TOR given the necessary instructions upon that division of art; having already in the previous pages of the POPULAR EDUCAnecessity of good drawing, and keeping up the practice of it, as but we shall not refrain from urging upon our pupils the in a great measure their success in painting will depend upon objects with the lead-pencil. Colours, like lines, must be put the ability they possess for representing the exact forms of is strictly that of drawing. We do not leave off drawing when in their right places, and the power of doing this in both cases and continue drawing, but with other materials. we put down the lead-pencil, we simply change the instrument The pupil is often too anxious to begin the painting and leave much of the drawing to be done, if possible, with the brush, sometimes from a total inability to carry out faithfully to the end what we should call a clear or severe outline, or from not understanding its importance: we can tell such, that if they find it difficult to represent the forms of objects truthfully with the pencil, they will not be able to fulfil their intention with the brush; and if they are desirous of finishing the picture quickly, we advise them to draw it well first, and so avoid the inevitable blotching erasures which would spoil its appearance, and cause so much discouragement. Nothing more readily exposes the defects in a drawing than filling it up with colour, for the errors and imperfections crop up as the painting advances, and many who have foolishly neglected to bestow a little more time and care upon the drawing, could testify to the discouragement and failure which usually follow. The amount of labour we resolve to bestow on a painting from Nature is influenced more or less by the extent to which we intend to carry out the subject. Drawings are generally termed sketches or studies, according to the time and attention devoted to them. A sketch only gives general impression of a scene without going into elaborate details, while preserving its true character as a whole, both with respect to form and colour; and although the less important details may be omitted, yet great regard must be paid to the truthfulness of the general masses, so as to exhibit their proportions, angles, contours, tones, and effects with the greatest fidelity. The other term, a study, indicates that all which in a broad and general manner was begun in the sketch, has been continued with further care and attention to details, and where every part has had a due proportion of thought and labour bestowed upon it, yet without destroying the effect as a whole. In the previous lessons upon drawing we have explained how, after a little practice, the general form and character in outline may be easily obtained. So also in these lessons we hope to show how much colour is capable of contributing its share of character and effect; and that, with persevering zeal and attention on the part of the pupils, the power of using it will not be more difficult to attain. The first impression the mind receives of a landscape is altogether a general one, all that a sketch might include; but if we desire to become better acquainted with it, we stop to examine it, and obtain a closer insight into its details; we then practically make a study of it. First impressions teach us that objects have about them |