The Great Fair.

THE EIGHTEENTH FAIR AT THE AMERICAN INSTITUTE, which is now open at Niblo's Garden, excels in splendor, variety, and tasteful arrangement, anything of the kind hitherto witnessed in this city. The managers have evidently acquired great perfection in the art of arranging to please, and displaying to advantage. We shall not attempt any description of the arrangement and variety in the several halls, galleries, &c., as it would be impossible to convey any correct idea of either the arrangement, variety, or splendor of the exhibition, to those who are not acquainted with the premises. The entries made by contribution of machines, manufactures, specimens of art, &c., amount to upwards of 1300, many of the lots of manufactures consisting of several hundred pieces. The exhibition is enlivened by excellent music, with occasional orations and songs; and we are gratified to observe that the halls are daily thronged with crowds of well pleased visitors; and the probability is, that the fair will continue open for two weeks longer. Of the immense variety, we can only mention a few articles, and those of a class which, to us, are particularly interesting.

Thayer's Bridge.—There are several beautiful models of bridges on exhibition, each of which claims peculiar advantages. One in particular, invented and patented by G. W. Thayer, of Springfield, Mass., has a very ingenious and peculiar arrangement of the timers and iron supports, which, to our mind, presents a greater combination of the strength of materials, than any other plan we have seen.

Hussey's Reaping Machine.—There are a great variety of excellent machines exhibited, many of them in full operation by steam power, and well worthy of notice; but one which, from the nature of its application, could not be thus exhibited, but which is evidently superior to anything of the kind which we have examined, is a machine for reaping grain, by Obed Hussey, of Baltimore, Md. With this machine, a man and boy, with one horse, will cut 16 to 20 acres of grain per day. it is surprising that farmers are so backward in adopting such a labor- saving invention.

Palmer's Computing Scale.—This is a revolving table, for solving mathematical problems, by a simple mechanical process. it consists of logarithmeric combination of numbers, arranged on two circles, one of which revolves within the other; so that, by the simple process of moving a circular card, the relation of the figures to each other is changed, so as to solve the most difficult problems. The invention must come into general use, though we have not learned where they may at present be procured.

Carpenter's Tools.—Of the almost endless variety of wares, manufactures and utensils, no specimen appeared to us more interesting, than the splendid assortment and rich variety of brilliant and excellent TOOLS exhibited by Henry Rowntree, from his store, No. 60 Chatham Street. And we may add the remark, that these tools are sold cheaper by Mr. Rowntree, than by any other dealer with whom we are acquainted.

Hoe's-Card Printing Press.—An excellent little portable press, recently invented and manufactured by R. M. Hoe, of this city, is exhibited in full operation, by Mr. Wm. Wait. It is easily managed by one man, and will turn out twenty cards or small bills per minute, very neatly printed. This machine excites much interest.

Colt's Repeating Pistols, having been brought to great perfection by recent improvement, are exhibited by the present proprietor, Mr. John Phelps, of No. 2 Barclay Street.

Lee & Co.'s Wire Window Shades, are admired by all who see them. They combine unsurpassed beauty and elegance, with almost indispensable utility. They are exhibited by Lee & Co., from 577 Broadway. We shall notice them again.

Gurney's Daguerreotypes.—There is a great competition in this branch, and many sets of superb specimens, by different artists, are exhibited; but we feel constrained to say, that a few of the specimens from the rooms of Mr. Gurney, 189 Broadway, approach nearer to absolute perfection, than anything of the kind we have seen: it is difficult to realize that they are not real life.

We should notice many other articles, but our limits will not admit of it at present.

ARISTOCRACY.—A young man of this city, who has recently been to Europe for the purpose of taking possession of a fortune bequeathed him by a relation, says it was a source of great amusement to him on his return, to see so many wealthy men extending their hands to him, and expressing great delight at seeing him again, although those same nabobs would have looked down on him with disdain, if he had presumed to speak to them, before he left New York. That is the way of the world.

THE CLOCK BUSINESS.—At Jerome's Factory, in New Haven, Conn., 50,000 clocks are manufactured per annum, requiring, in their construction, 500,000 feet pine lumber; 200,000 feet mahogany and rosewood veneers; 200 tons of iron for weights; 100,000 lbs. of brass; 300 casks of nails; 1,500 boxes of glass, 50 feet per box; 1,500 gallons varnish; 15,000 lbs. wire; 10,000 lbs. glue; 30,000 looking-glass plates.

A RABBIT FAST.—Two rabbits belonging to a gentleman in Alleghany city, were accidentally imprisoned in an unfrequented room, where they remained without food for three weeks before they were discovered. They were supposed to have strayed away, but were last week discovered, not only alive, but in apparent health. It was very unlucky for them that they had never learned to cry.

FORTUNATE ACTORS.—Charles Kean and his lady are reported to be worth $240,000. Forrest has invested $100,000. Macready cleared $50,000 during his recent visit to the United States; and the dancers—Celeste and Elssler, are both immensely rich. How flourishing this world would be, if everybody would turn actors and dancers.