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The discovery indeed was owing rather to chance than design; so that it is the good fortune of the discoverer, rather than his skill or ability, we are indebted to: on this account it concerns us the less to know, who it was that first hit upon this admirable invention. Be that as it may, it is certain it must have been casual, since the theory it depends upon was not then known.

John Baptista Porta, a Neapolitan, according to Wolfius, first made a Telescope, which he infers from this passage in the <hi rend="italics">Magia Naturalis</hi> of that author, printed in 1560: “If you do but know how to join “the two (viz, the concave and convex glasses) rightly “together, you will see both remote and near objects, “much larger than they otherwise appear, and withal “very distinct. In this we have been of good help “to many of our friends, who either saw remote “things dimly, or near ones confusedly; and have “made them see every thing perfectly.”

But it is certain, that Porta did not understand his own invention, and therefore neither troubled himself to bring it to a greater perfection, nor ever applied it to celestial observation. Besides, the account given by Porta of his concave and convex lenses, is so dark and indistinct, that Kepler, who examined it by desire of the emperor Rudolph, declared to that prince, that it was perfectly unintelligible.

Thirty years afterwards, or in 1590, a Telescope 16 inches long was made, and presented to prince Maurice of Nassau, by a spectacle maker of Middleburg: but authors are divided about his name. Sirturus, in a treatise on the Telescope, printed in 1618, will have it to be John Lippersheim: and Borelli, in a volume expressly on the inventor of the Telescope, published in 1655, shews that it was Zacharias Jansen, or, as Wolsius writes it, Hansen.

Now the invention of Lippersheim is fixed by some in the year 1609, and by others in 1605: Fontana, in his <hi rend="italics">Novæ Observationes Cælestium et Terrestrium Rerum,</hi> printed at Naples in 1646, claims the invention in the year 1608. But Borelli's account of the discovery of Telescopes is so circumstantial, and so well authenticated, as to render it very probable that Jansen was the original inventor.

In 1620, James Metius of Alcmaer, brother of Adrian Metius who was professor of mathematics at Franeker, came with Drebel to Middleburg, and there bought Telescopes of Jansen's children, who had made them public; and yet this Adr. Metius has given his brother the honour of the invention, in which too he is mistakenly followed by Descartes.

But none of these artificers made Telescopes of above a foot and a half: Simon Marius in Germany, and Galileo in Italy, it is said, first made long ones fit for celestial observations; though, from the recently discovered astronomical papers of the celebrated Harriot, author of the Algebra, it appears that he must have made use of Telescopes in viewing the solar maculæ, which he did quite as early as they were observed by Galileo. Whether Harriot made his own Telescopes, or whether he had them from Holland, does not appear: it seems however that Galileo's were made by himself; for Le Rossi relates, that Galileo, being then at Venice, was told of a sort of optic glass <cb/> made in Holland, which brought objects nearer: upon which, setting himself to think how it should be, he ground two pieces of glass into form as well as he could, and fitted them to the two ends of an organpipe; and with these he shewed at once all the wonders of the invention to the Venetians, on the top of the tower of St. Mark. The same author adds, that from this time Galileo devoted himself wholly to the improving and perfecting the Telescope; and that he hence almost deserved all the honour usually done him, of being reputed the inventor of the instrument, and of its being from him called <hi rend="italics">Galileo's tube.</hi> Galileo himself, in his <hi rend="italics">Nuncius Sid<*>us,</hi> published in 1610, acknowledges that he first heard of the instrument from a German; and that, being merely informed of its effects, first by common report, and a few days after by letter from a French gentleman, James Badovere, at Paris, he himself discovered the construction by considering the nature of refraction. He adds in his <hi rend="italics">Saggiatore,</hi> that he was at Venice when he heard of the effects of prince Maurice's instrument, but nothing of its construction; that the first night after his return to Padua, he solved the problem, and made his instrument the next day, and soon after presented it to the Doge of Venice, who, in honour of his grand invention, gave him the ducal letters, which settled him for life in his lectureship, at Padua, and doubled his salary, which then became treble of what any of his predecessors had enjoyed before. And thus Galileo may be considered as an inventor of the Telescope, though not the first inventor.

F. Mabillon indeed relates, in his travels through Italy, that in a monastery of his own order, he saw a manuscript copy of the works of Commestor, written by one Conradus, who lived in the 13th century; in the 3d page of which was seen a portrait of Ptolomy, viewing the stars through a tube of 4 joints or draws: but that father does not say that the tube had glasses in it. Indeed it is more than probable, that such tubes were then used for no other purpose but to defend and direct the sight, or to render it more distinct, by singling out the particular object looked at, and shutting out all the foreign rays reflected from others, whose proximity might have rendered the image less precise. And this conjecture is verified by experience; for we have often observed that without a tube, by only looking through the hand, or even the fingers, or a pinhole in a paper, the objects appear more clear and distinct than otherwise.

Be this as it may, it is certain that the optical principles, upon which Telescopes are founded, are contained in Euclid, and were well known to the ancient geometricians; and it has been for want of attention to them, that the world was so long without that admirable invention; as doubtless there are many others lying hid in the same principles, only waiting for reflection or accident to bring them forth.

To the foregoing abstract of the history of the invention of the Telescope, it may be proper to add some particulars relating to the claims of our own celebrated countryman, friar Bacon, who died in 1294. Mr. W. Molyneux, in his Dioptrica Nova, pa. 256, declares his opinion, that Bacon did perfectly well understand all sorts of optic glasses, and knew likewise the