Dr. Moll on the Invention of Telescopes. 495 



the invention of telescopes : in England, these instruments 

 were known at a much earlier period. The celebrated English 

 mathematician, Thomas Harriot *, actually observed the satel- 

 lites of Jupiter, as early as the 10th of January, 1610, which is 

 only eleven days later than Galileo's discovery. It is, indeed, 

 astonishing that an English author should overlook this circum- 

 stance. Harriot also observed the spots in the sun for the first 

 time on the 8th of December, 1610. They were first seen by 

 Galileo in November of the same year. Harriot's telescopes 

 had, it appears, powers of 10, 20, and 30. His observations 

 run from the 16th of January, 1610, to 26th of February, 

 1612 ; he gives drawings of the configurations and computation 

 of their revolutions. Now, it may be asked, from whence did 

 Harriot get the telescope with which he observed the satellites 

 only a few days later than Galileo ? Certainly not from Italy ; 

 he either made it himself, or got it from Holland. 



But a few months later we find another English astronomer 

 furnished with a telescope. Sir Christopher Heydon writes, 

 on the 6th of July, 1610, to the well-known William Camden : 

 ' I have read Galileo, and, to be short, do concur with him 

 in opinion ; for his reasons are demonstrative ; and of my own 

 experience, with one of your ordinary trunks, I have told eleven 

 stars in the Pleiads ; whereas no age ever remembers above 

 seven; and one of these, as Virgil testifieth, not always to 

 be seen y.' 



Telescopes were then, it appears, called trunks. Harriot, 

 in his letters to Henry Percy, Earl of Northumberland, calls 

 them perspective cylinders. It appears that the earl possessed 

 many of them, and that he wanted some more. It is to be 

 lamented that Harriot's papers and manuscripts are at present 

 buried, in one of the libraries of the University of Oxford. 



From all which has been said in this paper, the following 

 facts may be established, as proved by authentic documents : 



* These observations, and other manuscripts of Harriot, were discovered, in 1784, 

 by Baron de Zach, at Petworth, in Surrey, the seat of Lord Egremont. See 

 Bode's Astronom. Tahrbuch. 1788, p. 155, Monatliche Correspondenz, t. viii. 

 p. 144. 



t Gulielrai Camdeni et iilust. viror. ad G. Camden. Epistol. Loadou 1691, 

 p. 128. 



