This is certainly prior to the usual dates given for binary numeration. There is no guarantee that these things were original with Hariot, and some may be much older. But at least it is an instance of his knowledge. We may take Lower's praise how we will, but there is little doubt that Hariot's executors would have had material as interesting as the preliminary treatise.
More publicity has been given to Hariot's astronomical work, partly because of the dramatic discovery of the papers by Baron de Zach; and the encyclopedias tell how he used his early training in navigation in his observations of Halley s comet with a cross-staff. Sun-spots he watched with the naked eye, though he admits this gave him pain. Both Hariot and Galileo seem to have borrowed the telescope from the Dutch very shortly after its invention and to have used it simulta neously. With the help of his servant and instrument maker, Christopher Tooke, Hariot seems to have supplied his pupils with telescopes and asked their aid in observation. His own recorded observations go back to July, 1609, a month after Galileo's first construction; and partly independently and partly with the knowledge of the Italian he, too, observed the moon, the satellites of Jupiter and later the comet of 1618.
Some time, perhaps, there will be published extracts from the correspondence of the time, for it throws delightful light on the mental attitude of the scientists. Lower's letters, for example, are charming in their naïve statements. In the letter above quoted he begins
I have received the perspective Cylinder that you promised me and am sorrie that my man gave you not more warning, that I might have had also the 2 or 3 more that you mentioned to chuse for me. . . According as you wished I have observed the Mone in all his changes. . . . In the full she appears like a tarte that my Cooke made me the last Weeke. here a vaine of bright stuffe, and there of darke, and so confusedlie al over. I must confess I can see none of these without my cylinder. . . .
And when he wishes to compliment Hariot in another letter some five months later he says he has done more
. . . then Magellane in opening the streightes to the South sea or the dutch men that weare eaten by beares in Nova Zembla. . . .
Perhaps this last is not too high a compliment; but when the compliments to Hariot are discussed the truth will be seen of a statement made above. He has not been fairly treated. There are errors on both sides, from Montucla s curt dismissal to the adulation of Baron de Zach. To the latter Hariot s use of the telescope was proof of his inventing it, and a mark of superiority to Galileo. In short, more harm has been done to Hariot by his admirers than by his opponents; as in the controversy started by Wallis to prove that Descartes borrowed all his algebra from Hariot without acknowledgement, and hence that Hariot
