The Capucin friar, Rheita*, attributes also the first invention to Lippershey, whom he calls Lippensum. This is certainly no great alteration of the original name, not greater than that which is made by the English author of the Life of Galileo, who chooses to translate Borel's name into Italian, and calls him Borelli. According to the version of Rheita, the invention dates from 1609, when Lippershey happened to place a convex before a concave, and discovered, by chance, that the weathercock of a neighbouring church, and other objects, were magnified. He placed his glasses in a tube, and amused the visiters of his shop by showing them the weather-cock magnified, and larger than it could be seen with the unassisted eye. The Marquess of Spinola, happening to be at the Hague at the time, to negotiate about the truce, saw this new instrument, bought it, and gave it to the Archduke Albert of Austria, the Spanish Governor of Belgium.

In the mean time, persons of high station (proceres) heard of the circumstance, and that other similar instruments had been constructed by the maker. The inventor was forced to sell his instrument for a great price; but he was prohibited from making or selling any more of them. In this manner, says the worthy friar, this noble and capital invention would have remained in obscurity, and hidden perhaps for ever, if it had not been transferred, by the will of God, to the court of Brussels, and made known there.

The Capucin friar is mistaken in the dates, bringing the invention to 1609 instead of 1608. But, besides, the Marquess of Spinola was not at the Hague in 1609. He left that city the 30th of September, 1608, together with the other Spanish ministers. That he left the Hague a little before Lippershey presented his petition to the States; but the Marquess, residing at the Hague, certainly could not see an apparatus which a spectacle-maker had erected in his shop at Middelburg; but, at all events, there is a possibility that Spinola, residing at the Hague in September, 1608, heard of the invention, and produced a telescope for the Archduke.

* Oculus Enoch and Eliæ, p. 337.

(To be continued.)

Proceedings of the Royal Institution of Great Britain.

FRIDAY EVENING MEETINGS.

Jan. 21st.-THE meetings for the season commenced this evening, and will be continued every Friday, except those of Passion and Easter weeks, until the 10th of June. The subject in the lectureroom, upon the present occasion, was given by Mr. Faraday, being, in fact, the developement and illustration of that peculiar class of optical deceptions which forms the object of the first article in the present Journal, p. 205. The effects were shown by large wheels cut out of pasteboard: those produced, by casting the shadows of the moving wheels upon a screen, were exceedingly well exhibited by means of the cone of rays from a magic lantern. The appearances exhibited by reflection were also well shown; and, as some effects beyond those mentioned in the paper had been observed, and were explained, Mr. Faraday will add a note of them at the end of these proceedings.

In the library, Mr. Cuthbert showed the power of his beautiful microscope, by exhibiting some wheel animalculæ ; and Mr. Varley also exhibited more of these animals, by means of excellent microscopes in his possession; the object was to give the members an opportunity of seeing the appearance of this curious creature, that they might the better understand the references made to it by Mr. Faraday, in pursuance of his subject.

Numerous presents of specimens of natural history, books, engravings, &c. &c. were laid upon the library-table. Mr. Pepys brought to the meeting a very beautiful piece of American glass casting; it was a small plate, the upper surface smooth, but the under surface covered by a beautiful design of scroll-work, &c. in very high relief, so that, as the plate stood upon a table, the reflection of light from it was of the most brilliant and metallic kind. The plate had been cast, the wheel had never touched it, yet the surface

looked as well almost as if cut; and the pattern was so rich and full, and of such a kind, as to preclude any imitation of it by cutting. Mr. Pepys also placed a beautiful spiral metallic thermometer, by Breguet, upon the table.

NOTE BY M. F.

In consequence of the necessity I was under of sending the paper referred to in the above proceedings to press (page 205) by a certain time, I was unable to pursue many of the beautiful combinations of form, colour, and appearance, to which the experiments led, especially as they promised only amusement and little more of instruction than the paper itself contained; but one or two varieties in the appearances, which have occurred to me since, are so striking, that I am glad of the opportunity of noticing them briefly in the same number with the paper. At page 218, I have described the singular appearance produced when the reflected image of a revolving cog-wheel, held before a glass, is observed through the cog-wheel itself. If, in such a wheel, a little nearer the centre, a series of regular apertures be cut, so as to represent cogs and their intervals, but the number different by 1.2.3, or any small quantity, from the number of the cogs, then, upon making the experiment as before, that series of cogs in the revolving wheel through which the eye looks will appear to stand still, but the other series will travel in the spectrum: upon changing the eye to the other series of apertures, then the quiescent part of the spectrum will move, and the moving part become quiescent. If two or three series more of such apertures be cut in the wheel, concentric one to another, but the number of intervals varying in each, then a great variety of changes are produced, as the eye looks through one part or another of the wheel. The series of cogs in the spectrum move with different velocities, or in opposite directions, changing with the slightest motion of the eye. Two or three persons looking through different parts of the wheel see appearances

entirely different; yet all these deceptive appearances result from a single reflection of a single wheel, moving in a constant direction and with uniform velocity.

By the application of colours and coloured foils, very curious effects occur, which are endless in their variety. As an illustration, let a wheel with a single series of cogs at the edge, and with intervals equal to the cogs, have a circle of colour applied between the cogs and the centre of the wheel; let the part below the cogs be green, and the part below the spaces red; the coloured circle will consist of green and red alternately. If this wheel be revolved before the glass, the green and red mingle, and the reflection observed in the ordinary way will exhibit one uniform colour; but if the reflection be observed from between or behind the cogs, the green and red immediately separate, and besides having the appearance of fixed cogs, there is also the appearance of fixed unmingled colours. If the interval be equal to only half a cog, and three colours be applied, the three colours may, after being mingled by rotation, be again developed, and it is easy in this way to separate many colours from each other. The experiment in illustration of Newton's theory of colour, by painting the head of a top and spinning it, is well known; by the means just described the experiment can be still further extended, and the colours separated one from another, even while the whole system remains in motion.

The combination of other forms than wheels by the apparatus described, page 208, produces very beautiful effects. The application of colours here also is so evident as to need no illustration. The variation of the proportion of the interval to the remaining pasteboard causes many curious appearances, especially when the shadows produced in sun-light are observed.

Since the printing of the paper, a friend has referred me to the article Animalcula,' in Brewster's Encyclopædia, where an opinion on the appearance of these creatures is given, nearly the same as that I have ventured. Speaking of the opinions of those who suppose them to be true revolutions, it is said, Yet notwith

standing our respect for the skill and talents of such renowned naturalists, we cannot deny that we think the production of the vortex is more probably effected by the simple motion of the fibrilla-that it may ensue from their rapidly bending in regular or alternate succession, or by some analogous means.'

M. F.