heat of summer, unless it has upon it a desert of strawberries and cream. She ought also to consider her tea-table deficient unless strawberry-jam is among her preserves and sweetmeats, and who does not love an occasional bowl of strawberries and milk? But while we insist that every farmer's wife should furnish her table with delicious fruit, we would not compel her daughters "to go a strawberrying" in the oldfashioned way their grandmothers did-even were they so extravagantly fond of strawberries as to ramble about the fields, with their sun-bonnets on their heads, and strawberry-baskets in their hands in pursuit of them. If farmers would have strawberries, they must devote a small portion of their gardens to their cultivation. There are several varieties of excellent flavour, and by a judicious selection, and a little labour, a full supply may be had through the season. The ordinary method of cultivation is to prepare ground, by manuring and spading, and transplant in August. The distances between the rows generally from eighteen inches to two feet, between the plants from nine to fifteen inches, according to the varieties. The runners the first year are cut off just before they take root. Some cultivators cut off the leaves in autumn. The second year the runners are permitted to take their course filling up the spaces between the plants and producing ordinarily, a good crop of large-sized strawberries. Some lay down straw or grass for the runners to run upon. The utility of this is manifest in many respects, but especially in keeping the fruit from coming in contact with the earth by which it would be injured by dirt. After the fruit is gathered, the straw should be removed and the plants cleared of weeds. They should be transplanted every second year. Silk Culturist. MANUFACTURE OF GUNPOWDER. THE following description of the nature and manufacture of gunpowder, by an able chymist, (Dr. Ure,) will prove interesting: This explosive substance consists of an intimate mixture, in determinate proportions, of saltpetre, charcoal, and sulphur, and is better in proportion, every thing else being equal to the quality of these ingredients. The nitre, in particular, ought to be perfectly refined by successive crystallizations, and finally from adhering water, by proper drying, or by fusion in iron-pots at a regular heat. Nothing can surpass, in these respects, the nitre prepared in the government powdermills at Waltham Abbey. It is tested by adding to its solution in distilled water, nitrate of silver, with which it occasions no perceptible opalescence. The sulphur ought also to be of the finest quality, and purified by skimming, or even sublimation, if at all necessary. The charcoal should be newly made; it should burn without having any sensible residuum, be dry, sonorous, light, and easily pulverized. The charcoal for gunpowder is made either of alder, willow, or dogwood, the latter being preferred-which are cut into lengths and ignited by iron cylinders. It deserves notice that the proportion of powder used for the several pieces. from charcoal made in pits. The wood, before charring is carefully stripped of its bark. The three ingredients, being thus prepared, are ready for manufacturing into gunpowder. They are first separately ground to a fine powder, which is passed through proper sieves, or bolting machines; and, secondly, they are mixed together in proper proportions. These do not seem to be definitely determined, for they differ in different establishments of great respectability, as is shown by the following table :Nitre. Charcoal. Sulphur. Thirdly the composition is sent to the gunpowder mill, which consists of two edgestones of a calcareous nature, turning by means of a shaft on a bedstone of the same nature, which give no sparks, as sandstone would be apt to do. On this bedstone, the composition is spread, and moistened with as small a quantity of water as will, in conjunction with the revolving stones, bring it into a proper body of cake, but not paste. The line of contact of the edgestones is constantly preceded by a scraper, which goes round with the wheel, constantly scraping up the cake and turning it into the track of the stone. From fifty to sixty pounds are usually worked When the cake has been at once in each wheel. thoroughly incorporated, it is sent to the corning house, where a separate mill is employed to form the cake into grains or corns. Fourthly here it is first pressed into a hard, firm mass, then broken into small lumps; after which the graining is executed, by placing these lumps in sieves, on each side of which is laid a dise of lignumvitæ. The sieves are made of parchment skins, perforated with a multitude of round holes. Several such sieves are fixed in a frame, which, by proper machinery, has such a motion given to it, as to make the lignumvitæ runner in each sieve move round with considerable velocity, so as to break the lumps of the cake, and force the substance through the sieves, forming grains of several sizes. The granular particles are separated from the finer dust, by proper sieves and reels. Fifthly: the corned powder is next hardened, and the rougher edges taken off by being revolved in a close reel or cask, turning rapidly on its axis. This vessel somewhat resembles a barrel-churn; it should be only half full at each operation, and has frequently square bars inside, parallel to its axis to aid the polish by attrition. Sixthly: the gunpowder is now dried, which is done generally by a steam heat, or by transmitting a body of air lightly heated in another chamber, over canvass shelves covered with the damp gunpowder. Mining Journal. Hope is a prodigal young heir, and Experience of ordnance by the navy, &c., has been reduced is his banker; but his draughts are seldom honoured, one third, in consequence of the increased strength since there is often a heavy balance against him, of the composition into which this cylinder, charcoal, because he draws largely on a small capital, is not enters, compared with that manufactured formerly yet in possession, and if he were, would die. VOL. IV-25 MACKEREL FISHERY THE whole amount of tunnage employed in the cod and mackerel fisheries of the United States, for the year ending the 30th of September, 1834, was 107,430; of which, 48,725 tuns belong to the mackerel fishery. Of this aggregate amount, 35,196 tuns were owned in Massachusetts; 11,764, in Maine; 1,623, in New Hampshire; and 142, in Rhode Island. The vessels employed average from forty to fifty tuns each; and are found to have amounted, in 1835, to about 900 in Massachusetts, and from 300 to 400 in the three other states. Each vessel has an average of about nine persons, of all ages; making about 8,000 for Massachusetts, and say 3,000 for Maine, New Hampshire, and Rhode Island. Independently of the profit on their labour obtained by these persons, we have to consider that accruing on the construction and fitting out of the vessels, the manufacture of the barrels, the commerce on the salt consumed, the transportation of the fish coastwise, and all the subsidiary branches of industry connected with these its main departments. Of course, the advantageous influence of this business on the condition of those places where it is chiefly pursued, is very apparent. Its relation to other employments of a similar description may be inferred from the fact, that, of ninety-nine schooners built in Massachusetts in the year 1834, seventythree were in the five collection districts most largely engaged in this fishery. Though unproductive in some seasons, it has, on the whole, added greatly to the resources and economick prosperity of the communities engaged in its prosecution. But And the mode in which the business is conducted renders it invaluable as a school of maritime enterprise and nautical industry. Some of the vessels employed in the fishery are owned by merchants or others, who employ them in it during three or four months of the season, and in the coasting trade or some other business the residue of the year. the greater part of the vessels are owned by the fishermen themselves, or by them in connexion with merchants or mechanicks. It is no uncommon thing for several heads of families, who have sons of the age of nine years and upwards, to take a vessel, and man it from their families, and divide the proceeds among themselves: and as very young boys are thus capable of being useful in this pursuit, it is a great nursery of seamen for the navy and the merchant service. The crews are sometimes engaged on shares, receiving one half of the fish after they are salted; at other times, they are hired on wages. A very common method is, for the skipper and one or more of the crew to take the vessel, and hire the other hands; and pay to the owner, as charter, a fourth part of the proceeds, after deducting salt, barrels, butts, and some other supplies. By these means, the profits and incidental advantages of the business are made to diffuse themselves widely and thoroughly among the middling and poorer classes, without being accumulated, to any considerable extent, in the hands of capitalists. Mackerel are found on many parts of the coasts of Europe; but the fishery has never been pursued there to any extent. Some places in New Brunswick and Nova Scotia are favourably situated for the business; but they do not embark in it largely, partly from the absence of a domestick market, but still more for the want of adequate acquaintance with the proper process of dressing, curing, and putting up the fish, as it is done in the New England states. The superiour skill, enterprise, and calculation of our citizens, will continue to give us the advantage in this fishery, as in other branches of maritime industry. From the general table of the quantity of mackerel packed in Massachusetts, it is apparent how steadily and greatly this fishery has increased in productiveness. Taking successive periods of five years as an index of the increase, we have for the beginning only 8,079 barrels ; 8,866 for 1809; 1,349 for 1814, one of the years of the late war; 105,433 for 1819; 180,636 for 1824; 225,877 for 1829; and 252,844 for 1834. This rapid augmentation of the quantity taken, especially in the last twenty years, is one of the effects and the evidences of the unparalleled prosperity enjoyed by this country, and especially those portions of it in which this article is consumed. It is the increasing demand which, by stimulating to new activity, and to the invention of improved methods of taking the fish, has so much augmented the supply. And the market for the fish has been opened and expanded by the incomparable means of internal communication which the United States possess, in our noble rivers intersecting it like so many arteries, and covered with steamboats; and in our canals and railroads, permeating the country on all sides; and thus imparting to its most remote parts an harmonious correspondence of benefits, and that close interlacement of interests, which are among the great blessings of our admirable Union. The price of the article has, of course, fluctuated, according to the relative supply and demand; the first quality having taken the whole range of prices from $13 per barrel down to $4 50; and the supply, for the last three years, having fallen short of the demand, a gradual advance in prices has been the consequence. A small portion of the mackerel, consisting chiefly of the poorest quality, or No. 3, is exported to foreign countries. It is not easy to ascertain the precise quantity exported, as the annual statement, printed by order of Congress, embraces all kinds of pickled fish under one head; probably the amount does not exceed 40,000 barrels; they are sent to the West Indies, to South America, to some ports of the Mediterranean, and to the East Indies. But the principal market for this fish is in the United States. Philadelphia, New York, Baltimore, and New Orleans have taken the largest quantities hitherto; but more or less is shipped to most of the chief ports along the seaboard, from New York to New Orleans. Thus far, Philadelphia, by its rapid and steady increase of demand, has held the lead of other ports. From 1820 to 1825, that city required from 30,000 to 40,000 barrels as its yearly supply for its own consumption, its interiour trade, and its foreign or domestick export. It now receives three times that quantity, and about one third part of the whole product of the fishery. In the southern states, also, the demand increases with the increased facilities of interiour transportation, and must continue to be enlarged as the interiour of the country goes on acquiring access to markets and added population and prosperity. It is understood, also, that this fish. owing to its good qualities as an article of food, and its convenient form for subdivision and distribution almost any other fish of commercial importance. among the slaves, is gaining favour in the estimation So true it is, that fishermen who have pursued the of the planters of the South. As evidence of which business for a long period have but little advantage fact, it may be stated, by way of example, that, with over those recently engaged in it, in judging, with a coloured population of 210,000 persons, the state any degree of certainty, which may be the best spot of Georgia consumed the last year, 37,000 barrels, of fishing ground at any particular season of the of all qualities, valued there at $286,750. Doubt year. It is oftentimes the case, that vessels in exless, the consumption is proportionally great in the treme parts of the bay, and in nearly all intermediate other planting states. stations, will have good fishing for a few days, and for many succeeding days no mackerel will be visible; after which, they will appear to rise simulta These facts indicate the importance of the mackerel fishery as a domestick interest, which every part of the country is concerned in, and which is, there-neously, in nearly all parts of the bay; and in modfore, entitled to the respectful consideration of Con- erate weather large tracks of the surface of the sea gress. It only remains to show, in explaining the will seem to be covered with shoals of the fish, mode of taking this fish, what are the legal incon- swimming with one side of the gill out of water. veniences which this bill is designed to remove. At times, the fishermen can only take a few from a The season for the first appearance of mackerel, shoal, as it passes directly in contact with their veson those parts of our coast where they are usually sel, without being induced to stop by bait, or altertaken, is from the 20th of April to the 1st of May, ing its course in the least degree. It occasionally according as the season is more or less forward; at happens that late in the year the fishermen will reap which time they strike on the shore-soundings off a rich harvest, when the whole previous season had the capes of the Chesapeake and Delaware. Be- been comparatively unproductive. Thus it was in tween the latter place and the Egg harbours, they the autumn of 1831. In October of that year, the are usually plentiful for fifteen or twenty days, with- mackerel struck in very near to cape Ann. Large in a few leagues of the land; and mackerel vessels, fleets of vessels collected in such close order, as to which are on the ground seasonably, meet in gene-be continually coming in contact. The sea being ral with good success, if the weather prove to be favourable. After which, the mackerel move to the northeast, scattering over a large space of ground, from near the shore to the soundings inside the gulf stream, and extending down the coast off Long Island to Nantucket, which they reach early in June. Sometimes they collect more in bodies off Long or Block Islands, and are taken plentifully for a few days; after which, they proceed north, through the south channel, between the Vineyard islands, into Massachusetts bay. They reach that bay from the 20th of June to the 1st of July, and continue there until late in November. Large bodies of them pass up the bay of Fundy, as they are sometimes abundant between Grand Manan and Annapolis Royal, and doubtless proceed further in the same direction. Returning, they often follow the coast, striking into the bays in October and November, and passing out of Massachusetts bay by cape Ann and cape Cod, in the vicinity of which places they are sometimes found in abundance late in November. Meanwhile, other shoals of mackerel appear to approach our shores from the east, by cape Sable. Probably, this may be a portion of the body which annually enters the bay of St. Lawrence. Striking in from the gulf, on the Nova Scotia soundings, a part of them take a westerly direction towards Massachusetts bay, while the main body passes into the bay of St. Lawrence, east of cape Breton, and through the Guts of Canso. The time and place of spawning can be determined only by the different conditions of the fish, when taken at different times. In Massachusets bay, it appears to be, at a medium time, about the 1st of June. Notwithstanding their constant liability to be destroyed by other fish, from the moment of shooting spawn up to the time of their full growth, still their inconceivable number is such as to surpass all calculation. When the sea is smooth, they are seen absolutely covering its surface. Their movements and haunts are very precarious, and their habits are more versatile than those of smooth, and great quantities of bait thrown out, the fish collected in such quantities, that some vessels took nearly one hundred barrels in a single day. At the same time, they were very abundant off cape Cod and on Jeffries Ledge; and it was computed that more than 70,000 barrels were taken in a single week. Now, the habits of this fish being so uncertain, it frequently happens that a mackerel vessel, on the way to her fishing-ground, or when arrived at some fishing-ground which she may have been induced by previous success to select again, finds no mackerel, and, while waiting or seeking for mackerel, encounters abundance of other fish; by taking which, she might save her voyage; but which she is obliged to abstain from touching, in consequence of the rigorous terms of her license, which confines her exclusively to the business of taking mackerel. Vessels are sometimes under the necessity of shifting their ground, to avoid taking codfish in their mackerel-jigs. They may lose all the outfit and time of a trip, from the absence of mackerel, when they have absolutely to shun the presence of other fish, in consideration of the technical strictness of the law. OPTICKS. Be THE Science of Opticks affords scope for many delightful and interesting experiments; but some of its instruments are very expensive. I shall therefore state only a few simple exhibitions and experiments which can be made at a trifling expense. fore the teacher can illustrate any of the principles of this science by experiment, it will be requisite that he provide himself with a few convex lenses, some of short and others of pretty long focal distances. For example, double or plane-convex glasses, inch, 1 inch, 3 and 4 inches, focal distance, which may be made to illustrate the construction of a compound microscope, as I have elsewhere shown in my work, " On the Improvement of Society." Also lenses, from 3 to 6 or 8 feet focus, to illustrate the site the glass, where they will be beautifully depictconstruction of a telescope, and the nature of a cam-ed in all their forms, colours, and motions, in an inera obscura; and two or three concave mirrors for verted position, forming a kind of living picture.-illustrating some of the phenomena of reflection. This exhibition never fails to excite the admiration The principle on which a compound microscope, a of the young. If now, a lens about 2 inches focus solar microscope, and a magick lantern or phantasma- be placed 2 inches beyond the image thus formed, goria, are constructed, may be shown by one easy experiment. Let A, Fig. 1, represent a convex glass, suppose six inches focal distance, and B the flame of a candle. Hold the glass, A, at a little more than six inches from the candle, and on the Fig. 1. and the screen removed-in looking through this lens, the objects will appear magnified in the proportion of 2 inches to 60, that is, 30 times; and as the image was inverted, so the object, as seen through the glass, will appear as if turned upside down.This is perhaps one of the best modes of explaining the principle of a refracting telescope, and the reason why the object appears inverted, when viewed with a single eye-glass. The same thing may be partly shown by a common telescope. Having taken out all the eye-glasses, except the one next the eye, adjust the telescope to distinct vision, and all the objects seen through it will appear as if turned upside down. The manner in which the image is reversed by the other eye-glasses, and the object made to appear upright, might then be explained. Objects might likewise be exhibited through a telescope, as appearing in different positions and directions. This is effected by means of a diagonal eye-piece, which is constructed in the following manner:-Let A B, Fig. 2. A B EF D opposite wall will be formed a large magnified image of the candle, C E D. This image will be inverted, and larger than the flame of the candle in proportion as the distance A E, from the glass to the wall, exceeds the distance A B, from the glass to the candle. Suppose the distance A E to be 7 feet or 84 inches, then the image of the candle will be magnified in the proportion of 7 to 84, or 14 times. In this experiment the candle represents the object to be magnified in a compound microscope, A the object-glass, and C D the image formed by the lens, Fig. 2, represent a convex glass about 2 inches focal which is magnified a second time by the eye-glass of distance; C D a plain metallick speculum, of an oval the microscope. In reference to the solar micro-form, well polished, and placed at half a right angle scope, the candle represents the small object to be to the axis of the tube; and E F, another convex magnified, and C D its magnified image on a white lens, 2 inches focus. The centre of the speculum wall or screen; and in reference to the magick lantern, or phantasmagoria, the candle represents the figures painted on the sliders, A the convex lens which throws the image of the figures on a screen, and C D the magnified image of the painted figures. In all these instruments, the principle on which the objects are magnified is precisely the same; the size of the image is always in proportion to its distance from the lens by which it is formed; but as the image is enlarged it becomes less brilliant and distinct, and therefore there is a proper medium which must be fixed upon as to the distance between the lens and the screen on which the image is thrown; but a skilful teacher will always know how to modify such circumstances. The nature of a telescope and of the camera obscura may be illustrated as follows:-Fix a lens of 4, 5, or 6 feet focus, in a hole made in a window-shutter; darken the room, so that no light can enter but through the lens.* If its focal distance be 5 feet, or 60 inches, a white screen placed at that distance will receive the image of the objects without, oppo * A lens is a round piece of glass, ground either concave or convex. All lenses that magnify objects are conver, or thicker in the middle than at the edge, such as common magnifiers, readingglasses, and the glasses used in microscopes and telescopes, except the Galilean perspective, in which the eye-glass is concave. may be about 14 inch from A B, and about inch from E F. The rays proceeding from the lens A B, and falling from the speculum, are reflected in a perpendicular direction to the lens E F, where they enter the eye, which looks down upon the object through the side of the tube. When this eye-piece is applied to a telescope, with the lens E F on the upper part of it, we look down upon the object as if it were under our feet. If we turn the eye-piece round in its socket a quarter of a circle towards the left, an object directly before us in the south will appear as if it were in the west, and turned upside down. If, from this position, it is turned round a semicircle towards the right, and the eye applied, the same object will appear as if it were situated in the east; and if it be turned round another quadrant, till it be directly opposite to its first position, and the eye applied from below, the object or landscape will appear as if suspended in the atmosphere above us. Such experiments, when accompanied with proper diagrams, and an explanation of optical principles, may easily be rendered both entertaining and instructive. A camera obscura, on a larger scale, and on a different plan from that alluded to above, might be erected on the top of every school-house, which is constructed with a flat roof, as formerly suggested II Fig. 3. T K Fig. 3 contains a representation of a wooden building, on the top of which is a large convex lens, HI, about 10 or 12 feet focal distance. At half a right angle to this lens is a plain speculum by which the rays of light from the objects O are reflected downwards through the lens, which forms a picture of all the objects before the speculum, on a round white table, T, in all their colours, motions, and proportions. If the speculum be made to revolve, the whole of the surrounding landscape may be successively depicted on the table. When the lens is of a long focal distance, as from 10 to 15 or 20 feet, it produces a pretty powerful telescopical effect, so that objects may be distinctly perceived at a considerable distance, and individuals recognised on the picture at the distance of a mile or more. Wherever there are objects in motion, such as ships sailing, birds flying, smoke ascending, crowds of people moving to and fro, or boys and girls engaged in their amusements; this exhibition always affords a high degree of satisfaction. It might occasionally be used, not only as an illustration of optical principles, but also as a reward for diligence and good behaviour. ces infused, will be perceived in vast numbers, bythe aid of the microscope, in every drop of the infusion. A compound microscope is perhaps as good an instrument as any other for giving a steady and satisfactory view of such objects; and the only objection to its use for a school is, that only one individual can see the object at a time. When a teacher is not furnished with an instrument of this kind, fitted up in the usual way, he may, with little trouble, construct a compound microscope, by means of the eye-piece of a common pocket acromatick telescope, which may be purchased for one guinea, or less.The eye-pieces of such telescopes contain four glasses, arranged on a principle somewhat similar to that of the glasses of a compound microscope. If we screw off one of these eye-pieces, and look through it in the usual way, holding the object end about a quarter of an inch distant from any small object, such as the letters of a printed book, it will appear magnified about ten or twelve times in length and breadth; remove from the tube the third glass from the eye, which is the second from the object, and look through it in the same manner, holding it more than an inch distant from the object, and it will appear magnified more than twenty times in diameter, or above 400 times in surface. If, by means of small pasteboard tubes, or any other contrivance, we attach the glass that was taken out to the outside of the object-glass of the eye-piece, so as to be nearly close to it, we shall have a magnifying power of nearly forty times; or, if we substitute for these two object-glasses a single glass of about a half-inch focal distance, we shall form a pretty good compound microscope, magnifying above forty times in diameter, and 1600 times in surface, which will afford very pleasing views of various objects in the animal and vegetable kingdoms. The magnifying powers now stated will differ somewhat in different eyepieces, according to their lengths and the focal distances of the glasses of which they are composed. The tube of the eye-piece thus arranged, may be occasionally fitted into a pasteboard tube supported by three pillars, in which it may be moved up or down for adjusting it to distinct vision, and the object placed underneath and properly illuminated.These hints are suggested, on the score of economy, for those who have no regular microscopick apparatus. In connection with the above, representations might be given of natural and artificial objects, as exhibited by the phantasmagoria. Discarding the ridiculous and childish figures which were formerly used in the common magick lanterns, opticians have now constructed sliders which exhibit representations of the telescopick appearances of the heavenly Various amusing experiments, besides the above, bodies, the different constellations, the motions of might be exhibited to the young, such as the optical the earth and moon, and various objects connected paradox, an instrument through which objects may with botany, mineralogy, and zoology; and such ob- be seen, although a board or other opake body be jects, when exhibited in this manner, are calculated interposed between the eye and the objects-the to produce both instruction and amusement. The prism, which, in a dark room, separates the primary solar microscope in particular, (or the oxy-hydrogen, colours of the solar rays-the multiplying-glass, if it can be procured,) should be occasionally exhib- which makes one object appear as if there were ited to the young, to convey to them some ideas of ten, twenty, or thirty-the burning-glass, which, by the wonderful minuteness of the atoms of matter, means of the sun's rays, sets on fire dark-coloured and the admirable mechanism displayed in the paper, wood, and other inflammable substancesstructure of vegetables and the bodies of animals, and optical illusions produced by the various refracparticularly in those myriads of animalcula which tions and reflections of light in water, combinations are invisible to the unassisted eye. Such animal- of plane mirrors, and by concave speculums. A culæ may be procured almost at any season, but particularly during the summer months, by infusing, in separate open vessels, small bits of grass or hay, leaves of flowers, or other vegetable substances, when, after a week or ten days, animalculæ of different kinds, according to the nature of the substan concave mirror, about 5 or 6 inches in diameter, and 10 or 12 inches focus, which may be procured for about half a guinea or 15 shillings, is of great utility for a variety of exhibitions. 1. When held at nearly its focal distance from one's face, it represents it as magnified to a monstrous size. 2. When |
