Coloured, a curious phenomenon in optics, which was observed by Professor Scheffer of Vienna, and afterwards by Count Rumford, who made the discovery while prosecuting his experiments on light.

"Deformes," says the count, "of comparing the intensity of the light of a clear blue sky by day with that of a common wax candle, I darkened my room, and letting the day-light from the north, coming through a hole near the top of the window-shutter, fall at an angle of about 75° upon a sheet of very fine white paper, I placed a burning wax candle in such a position that its rays fell upon the same paper, and, as near as I could guess, in the line of reflection of the rays of day-light from without; when, interposing a cylinder of wood, about half an inch in diameter, before the centre of the paper, and at the distance of about 2 inches from its surface, I was much surprised to find that the two shadows projected by the cylinder upon the paper, instead of being merely shades without colour, as I expected; the one of them, that which, corresponding with the beam of day-light, was illuminated by the candle, was yellow; while the other, corresponding to the light of the candle, and consequently illuminated by the light of the heavens, was of the most beautiful blue that it is possible to imagine. This appearance, which was not only unexpected, but was really in itself in the highest degree striking and beautiful, I found upon repeated trials, and after varying the experiment in every way I could think of, to be so perfectly permanent, that it is absolutely impossible to produce two shadows at the same time, from the same body, the one answering to a beam of day-light, and the other to the light of a candle or lamp, without those shadows being coloured, the one yellow, and the other blue.

"If the candle be brought nearer to the paper, the blue shadow will become of a deeper hue, and the yellow shadow will gradually grow fainter; but if it be removed farther off, the yellow shade will become of a deeper colour, and the blue shade will become fainter; and the candle remaining stationary in the same place, the same varieties in the strength of the tints of the coloured shadows may be produced merely by opening the window shutter a little more or less, and rendering the illumination of the paper, by the light from without, stronger or weaker. By either of these means, the coloured shadows may be made to pass through all the gradations of shade, from the deepest to the lightest, and SHAFTESBURY, a town of Dorsetshire in England, in W. Long. 2. 20. N. Lat. 51. 0. It stands on a high hill, and is built in the form of a bow. It enjoys a serene wholesome air, and has a fine prospect. It is a good thoroughfare, governed by a mayor, and sends two members to parliament. This town is supposed to have been built in the 8th century, and to have been enlarged by King Alfred; and had 12 churches, besides a Benedictine monastery, in the time of the Saxons, but has now only three. St Edward the martyr was buried here. It had three mints before the conquest, and, in the reign of Henry VIII, was the see of a suffragan bishop.

SHAFTS, or Suffras, Gregory Savarof, an Armenian merchant, remarkable only as the person who sold the large and celebrated diamond which is now set in the imperial sceptre of Russia. Shah Nadir, an Indian prince, had two principal diamonds in his throne, one of them denominated the Sun of the Sea, and the other the Moon of the Mountain. When that prince was assassinated, many precious ornaments belonging to the crown were pillaged, and privately disposed of by the soldiers who shared the plunder. See DIAMOND, under MINERALOGY, where the account given of this diamond is somewhat different.

Shafras, who was called Millionik at Altracan, then had his residence at Baffora, with two of his brothers. A chief of the Armenians one day applied to him, and proposed to sell the diamond already mentioned for a very moderate sum (probably the Moon of the Mountain), together with a very large emerald, a ruby of considerable size, and other precious stones of less value. Shafras was astonished at the offer; and giving out that he had not a sufficient sum to purchase them, he requested time to consult with his brothers on the subject. The vender did not again make his appearance, probably from suspicious motives. Shafras, with the approbation of his brothers, went directly in search of the stranger with the jewels, but by that time he had left Baffora. Shafras, however, accidentally met him at Bagdad, and paid him 50,000 piastres (£933l. 6s. 8d.) for all his jewels. Shafras and his brothers being well aware that the most profound secrecy was absolutely necessary, resolved to remain at Baffora.

At the expiration of 12 years, Shafras set off with the largest of the jewels, directing his route through Sham and Constantinople, and afterwards through Hungary and Silegia to the city of Amsterdam by land, where he publicly offered them for sale.

It is reported that the British government was among the bidders. The Russian court sent for the large diamond, with an offer to reimburse all reasonable expenses, if the price could not be agreed on. When the diamond arrived, Count Patin, the Russian minister, made the following offer to Shafras. Besides the patent of hereditary nobility, which the vender demanded, he was to receive an annual pension of 6,000 rubles during life, 500,000 rubles in cash (112,500l. Sterling), one-fifth of which was to be payable on demand, and the remainder by instalments in the course of ten years. He also claimed the order of nobility for his brothers, persisting so obstinately in his demands, that the diamond was returned.

Shafras was now very much perplexed. He had involved himself in expenses, was forced to pay interest for considerable sums of borrowed money, and he saw no prospect of selling the jewel to advantage. The negotiation was recommenced with Russia by Count Gregory Grigorievitch Orloff, afterwards created a prince of the empire; and the diamond was purchased for 450,000 rubles (103,250l.) ready money, together with a grant of Russian nobility. We are informed that 120,000 rubles (27,000l.), fell to the share of the negociators, for commission, interest, and similar expenses. Shafras settled at Altracan; and his riches, which by inheritance devolved to his daughters, have been in a great measure dissipated by the extravagance of his sons-in-law.

SHAFT of a Column, in Building, is the body thereof between the base and capital; so called from its straightness. See ARCHITECTURE.