One day in November, 1582, he tells us that as he was at prayer, there appeared to him the angel Uriel at the west window of his museum, who gave him a translucent stone, or crystal, of a convex form, that presented apparitions, and even emitted sounds; so that the observer could hold conversations, ask questions, and receive answers from the figures he saw in this mirror.
With this speculum, black-stone, or show-stone, Dee used to "call his spirits," and Kelly, his associate, "did all his feats upon." Kelly, who acted as seer, reported what spirits he saw, and what they said; whilst Dee, who sat at a table, recorded the spiritual intelligence. A folio volume of their notes was published by Casaubon; and many more, containing the most unintelligible jargon, remain in MS. in the British Museum, together with the consecrated cakes of wax, marked with mathematical figures and hieroglyphics, used in their mummeries.
At length, Dee fell into disrepute; his chemical apparatus, and other stock in trade, were destroyed by the mob, who made an attack upon his house; but the mirror is stated to have been saved. It subsequently passed into the collection of the Mordaunts, Earls of Peterborough, in whose catalogue it is called the black stone, into which Dr. Dee used to call his spirits. From the Mordaunts it passed to Lady Elizabeth Germaine, and from her to John, Duke of Argyle, whose son, Lord Frederick Campbell, presented it to Horace Walpole; and on the breaking up of the collection at Strawberry Hill in 1842, this precious relic was sold: it was described in the catalogue as "a singularly interesting and curious relic of the superstition of our ancestors on the celebrated speculum of Kennel coal, highly polished, in a leathern case."
Bulwer, in his romance of Zanoni, introduces a mirror of this kind; and every tale of superstition has its magic glass. It is worth while to compare Dee's speculum with the celebrated ink mirror described in Lane's work on the Modern Egyptians; it may, at least, illustrate the curious inquiry upon coincident superstitions.
VOYAGE OF MANUFACTURE.
The produce of our factories has preceded even our most enterprising travellers. Captain Clapperton saw at the court of the Sultan Bello, in the interior of Africa, pewter dishes with the London stamp, and had at the royal table a piece of meat served up on a white wash-hand basin of English manufacture. The cotton of India is conveyed by British ships round half our planet, to be woven by British skill in the factories of Lancashire. It is again set in motion by British capital, and transported to the very plains whereon it grew; and is repurchased by the lords of the soil which gave it birth, at a cheaper price than that at which their coarser machinery enables them to manufacture it themselves. At Calicut, (in the East Indies,) whence the cotton cloth called calico derives its name, the price of labour is a fraction of that in England, yet the market is supplied from British looms.
SIR DAVID BREWSTER'S KALEIDOSCOPE.
The idea of this instrument, constructed for the purpose of creating and exhibiting a variety of beautiful and perfectly symmetrical forms, first occurred to Sir David Brewster in 1814, when he was engaged in experiments on the polarization of light, by successive reflections between plates of glass. The reflectors were, in some instances, inclined to each other; and he had occasion to remark the circular arrangement of the images of a candle round a centre, or the multiplication of the sectors formed by the extremities of the glass plates. In repeating, at a subsequent period, the experiments of M. Biot on the action of fluids upon light, Sir David Brewster placed the fluids in a trough, formed by two plates of glass, cemented together at an angle; and the eye being necessarily placed at one end, some of the cement, which had been pressed through between the plates, appeared to be arranged into a regular figure. The remarkable symmetry which it presented led to Dr. Brewster's investigation of the cause of this phenomenon; and in so doing, he discovered the leading principles of the kaleidoscope.