namely, in the summer of 1838; and the Fleetwood light-house, which was commenced in the summer of 1839, was lighted on the 6th June, 1840, upward of five years since; since which time, with the exception of a little paint, we understand that neither house has required the smallest repair."

Cast-iron towers are being gradually introduced, and have been built at Jamaica, Bermuda and Ceylon. "The chief alleged advantages of the cast-iron over the stone and brick towers are these: cheapness, facility of erection in any place, greater strength against vibrations in hurricanes, freedom from injury by lightning in tropical climates, and against the chances of earthquakes or fire."

"The light-house towers of France are constructed in the most substantial and perfect manner possible, without there being any appearance of unnecessary or wasteful expenditure. Great care is taken in the interior arrangements of the buildings, so that they may best answer the requirements of the service. Many of the towers are constructed of a soft stone of a rather peculiar kind, which hardens by exposure to the action of the atmosphere; those constructed of that material are lined inside with brick, leaving a sufficient space between the interior of the outer wall and the brick to allow a free circulation of air, thereby securing the building from dampness. Hard burnt bricks are preferred for light-house towers, when circumstances will admit of their being employed, particularly in fitting up the oil apartments, which are placed below the surface of the earth, to insure as equable a temperature during the whole year as may be possible to attain. The keepers' apartments are finished and fitted up in a plain, substantial, and economical manner, combining all the necessary accommodation and comfort. There is a room fitted up, and properly furnished, for the accommodation of the engineer, inspector, or other person authorized to make official visits at each light station. Especial care is taken to secure proper ventilation to the towers and lanterns-all the necessary fixtures about the lightrooms, lanterns, apparatus, &c.—the most minute, and apparently unimportant details in the exterior and interior arrangements; in short, nothing could combine greater perfection in stability, in usefulness, and a proper economy, than is perceptible in everything connected with the lighthouses visited by us on the coasts of France." In Prussia the buildings are chiefly of stone. In 1843 a small iron one was erected at Dantzic for a harbor light.

III. The lighting Apparatus.-The lights of Trinity Corporation are fixed, revolving, flashing, colored, double, &c., &c. The number of burners varies from 1 to 30. The reflectors are generally 21-inch parabolas.

"The lanterns and lighting apparatus are constructed with the same regard to stability and durability as in the construction and fitments of the buildings; the frames for the lamps and reflectors are of iron, very solidly fitted together, and the lamps and reflectors so securely placed that it would be almost impossible to get them out of their proper positions; the light-rooms are large, and of good height; the glazing is ordinarily of thick plate-glass, of 30 inches broad to 24 inches high, set into composition metal frames, and the roof of the lanterns of copper. The light-rooms and domes of the lanterns are

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painted white, and they retain their cleanly appearance, by care and an occasional application of soap and water, for a considerable length of time; the lanterns are free from smoke, notwithstanding the different methods that are employed to produce a proper ventilation."

"The material for burning in the English lighthouses is pure "winter bagged sperm oil." The results of the experiments to test the value of different gases for light-house purposes, have not been satisfactory to the Trinity board, or sufficiently so to warrant their introduction into any of the lighthouses under its control. They regard the sperm oil, or refined rape seed (colza) oil, as preferable materials; the latter is the cheaper in England; it has not, however, been generally introduced. In fact, the determination to use it at all is of very recent date."

Gas is used in local lights with great success. The same is true of Scotland.

Mr. Allan Stevenson, in his report to the House of Commons, says: "No success has attended any attempt to render the Drum mond light, which was at that time a subject of so many experiments, at all applicable to light-house purposes; nor am I aware that any one has ever indicated the direction in which inquiry might, with the greatest chance of success, be employed. All the changes that have been proposed have consisted in burning various gases under certain modifying circumstances; but I see no reason for believing that an increase of intensity sufficient to warrant the introduction of gas into light-houses has been obtained. Its use is unquestionably attended with risk of irregular exhibition in situations so remote as most lighthouses are; and in some situations it is wholly inapplicable (as in the Bell Rock and Skerryvore), and also in all revolving lights on the reflecting principle. In ordinary weather the present lights are seen as far as the curvature of the earth allows; and unless a light powerful enough for the penetration of a fog can be found, I see no inducement to run any risk as to the due and regular exhibition of the light, for the sake of any small increase of its intensity."

"The lights of Ireland, with one exception, are fitted with parabolic reflectors, made of copper, and silver plated, generally of 21 inches diameter, although some are larger. The burners used are Argand, about seven-eighths of an inch in diameter, constructed on the last and most approved plan. The number of reflectors for each lighthouse varies from 1 to 27. The lamps and reflectors are made at the Soho works, Birmingham, as a general rule.

"At present there is but one dioptric light in Ireland (at St. John's Point). It was constructed at Newcastle-upon-Tyne, by Cookson. There are three others proposed; one to be placed in a new tower, and the other two in old towers. The dioptric system is advocated by the engineer upon the score of economy, as well as superiority of light produced.

"The French mechanical lamp is employed successfully in the St. John's light-house, and the same kind of lamp will be used in the three proposed lights when ready for lighting. Mr. Halpin, the assistant inspector (engineer), does not approve of Mr. Wilkin's catoptric lamp for reflectors. The Argand is preferred by him.

The lanterns are of iron, with strong, though not thick sashes:

with glass three-eighths of an inch thick, and ordinarily 40 by 24 inches. The best plate-glass is used only; and the frames of the lanterns constructed with particular reference to their not obstructing unnecessarily the light by being too heavy. The domes are of copper; no lightning rods, that we saw. Particular care is bestowed upon the ventilation of the towers and lanterns; although, as yet, Dr. Faraday's tubes have not been introduced.

There are only five modes of distinction employed in Ireland, viz.: fixed white, fixed red, revolving white, revolving red and white, and intermitting lights.

"All the lights, buoys, beacons, &c., of Ireland, are supported by light dues, as in England and Scotland. The duties are one-quarter of a penny per ton for each light passed. No dues are levied for buoys and beacons. Harbor lights, being under the management of the ballast board, are placed upon the same footing as the public general or sea-coast lights. All supplies, as a general rule, are furnished by contract. The contracts are entered into upon sealed tenders, notice having been given for a sufficient length of time in the newspapers, of the articles required. The contracts are entered into annually for all articles for the ensuing year. Provisions, supplied under contract, are furnished to the men on board of the light-vessels in addition to their wages."

(To be continued.)

Art. II.—SUGAR—ITS CULTIVATION, MANUFACTURE, AND COMMERCE.

No. I.*

VEGETABLE PRINCIPLES-PROPERTIES OF CANE SUGAR-RE-AGENTS -MOLASSES, TREACLE-CANE JUICE-SACCHARINE MATTER

ANALYSIS OF SUGAR CANE, VARIETIES OF SUGAR MILLS-MOTIVE POWERS, ETC.

THE extraction of sugar from its juices is said to be a purely chemical process, and of consequence most perfectly conducted wherever science prevails the most. In the manufactories of the metropolis it will be found in a much higher state of advance than in colonial workhouses and estates, however extensive.

In the United States we have been latterly convinced of this, and are taking those steps which are suggested. The extraordinary advance which Louisiana evinces, speaks volumes for this better spirit.

We have been for some time collecting everything that could be had upon sugar as cultivated and manufactured at home and abroad, and have published many able articles from different sources of highest character. In this search we spare no pains, intending to prosecute it to the utmost extent. We have sent to Europe for material, and already been furnished with much that is valuable by an intelligent correspondent at London. The results in our own country are continually forwarded us. Our present article is the first of a series which shall embrace everything. We believe that the sugar planters and manufacturers of our country will sustain this enterprise and labor, which is likely to prove so valuable to them. We beg their co-operation and corre spondence upon this subject. As we progress, plans of machinery in every mode of preparation and improvement will be published without regard to expense. Our pres ent number is based upon the valuable work of Dr. Evans, about to be published in England, a copy of which has been sent us in advance, by a friend in that country. For other valuable information upon sugar, the reader will refer to our Review, Vol. I, 53, 54, 380; II., 322, 212, 214, 267, 422; III., 118, 231, 233, 245, 580, 248, 269, 294, 299, 301, 341, 376-395, 442; IV., 41, 128-136.

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Her liberal planters pause at no pains or expense; many of them are ever engaged in prosecuting their experimental researches; the progress is continual, and the effort unremitting. Were it not invidious, we could call by name many of these planters; some of them have sent agents to Europe to examine machinery and movements. The expense of improvement and apparatus is the last consideration; the great point is perfection.

Oxygen, hydrogen, nitrogen and carbon are the chemical constituents of all substances produced by the vital action of plants. Thus the water taken up by the roots and carried into the leaves, as sap, to be exhaled, to liberate oxygen, etc., thus changing its character, to return fit for the nutrition of the plant, contains two of these elements. "All the proximate principles which enter into the structure of a plant, are formed by a blending together of their elementary bodies in various proportions."

If inany of these compounds nitrogen be present, it is said to be azotized, if otherwise, non-azotized. Thus dextrine, starch cellulose, lignin, or woody fibre, gums, mucilage, and sugar, are of the latter class.

But sugar is also a product of the animal kingdom; thus, the sugar of milk, of diseased urine, etc. Vegetable sugar is that of the cane of fruits, of manna, etc. The glucose, or fruit sugar, is uncrystalizable, undergoes rapid vinous fermentation, and has a peculiar combination of elements. Mannite, the ingredient of manna, is contained in the juice of plants in New South Wales, and certain sea-weedsdoes not ferment. The cane-sugar consists of carbon, 12 atoms; hydrogen, 10 atoms; oxygen, 10 atoms; and 1 atom water. Sugarcane absorbs readily the chloride of sodium and potassium, and probably the sulphates. Where these salts abound in soils the sugar will possess purgative qualities. The sodium, or common salt, forms a deliquescent compound, and thus the difficulty of crystalizing sugar made from saline soils.

Cane sugar may also be obtained from many grasses, maize, guinea corn, roots of the carrot, beet, &c.; from pumpkins and melons, from the sap of the palm, &c. When pure, it is solid, transparent, and colorless; crystals, rhomboidal prisms; but subject to modification; soluble in half its weight of water at 60°, and at boiling point, sparingly in cold alcohol; specific gravity, 1600, water being 1000; at 300° it melts, and forms an uncrystalized mass, which, on a much greater application of heat, becomes uncrystalizable; at 500° the black substance caramel is formed.

The sugar cane is cultivated chiefly in the West Indies, Brazil, Louisana, and the Mauritius, and is of the following chief varieties:

1. Common or Creole cane, so called from being introduced from the new world. 2. Yellow Bourbon.

3. Yellow Otaheite.

4. Otaheite, with purple bands.

5. Purple Otaheite.

6. Ribbon cane.

The Muscovado sugar is all such as contains any foreign matters, as silica, phosphate of lime, carbonate of lime, organic matter, potash; being the state of all colonial and plantation sugars.

Molasses is the mother liquor after the crystalization of cane su

gar. It contains pure sugar and impurities. Twenty pounds Louisiana molasses gave 15 lbs. of the former, and 5 of the latter, including water.

Treacle is a late product of the refinery; it does not crystalize; is of a dark brown color; specific gravity, 1380-1400.

The plant is perennial. The stem, cut horizontally, is shown in figure 1, and when examined by a microscope, shows a series of hexagonal cells, formed of delicate tissue and closed laterally above and below, each being entirely independent. A series of vessels inclosed in woody sheaths is also found, and best shown by a vertical section.

Thus, A A, fig. 2, are the vessels; B B, the cells; the former being formed of rings, and running from one extremity to the other of the joint, forming a lacework. Here are situated the knots. The eyes, or germinal spots of the plant are found here. The vessels contain a crude sap or fluid; the cells a solution of pure sugar and water. Between these there would appear to be a continual communication. The sugar cells supply nourishment to the rapidly vegetating cane, but this supply is discontinued on maturity.

Cane-juice is the expressed product of crushed cane, and of consequence, consists of other substances besides sugar and water.

It is first opaque, frothy, and of a yellowish green or greyish; sweet taste; acid reaction on test-paper, and separable by filtration into a transparent yellow fluid, and a dark green fecula. This fecula or scum, when separated by heat and lime, consists of wax 7.5, green matter 1.3, albumen and wood 3.4, bi-phosphate of lime 0.5, silica 2.1, and water. The transparent liquid consists of water, sugar, saline matters, coloring principles, etc.

The experiments of Peligot and Evans on filtered cane-juice prove

1. That cane-juice, without the addition of any foreign matter, when its water is evaporated at the ordinary temperature of the atmosphere, does not produce crystals of sugar.

2. That when it is exposed to a temperature a little below that of