Caption: "Portrait believed to be of Thomas Harriot (c.1560--1621) (also spelt "Harriott" or "Hariot"), an English astronomer, mathematician, translater, ethnographer, explorer, and Renaissance man apparently painted during his lifetime.'' (Somewhat edited.)

Features:

1. Harriot would be a much more famous person than he is if he'd bothered to publish some of his important discoveries and innovations. In fact, he would rank with Galileo (1564--1642) and Johannes Kepler (1571--1630)---though a bit below---as one of leaders of Scientific Revolution (c.1543--c.1687). But he did NOT publish, and so he is mostly just an interesting specimen in the history of science.

2. An important example of Harriot's unpublished works is his Moon maps. He drew these starting from 1609 Jul26 (see Wikipedia: Thomas Harriot: Later years) some months before Galileo. But Galileo published promptly in the Sidereus Nuncius (1610, in English The Star Messenger), and so got all the credit---which is just since what good is a discovery that no one knows about. The Moon maps of Galileo and Harriot's are comparably good scientifically, but Galileo was a better artist.

3. Harriot's Moon maps show craters, crater rim shadows, the lunar maria and the Leaping Moon Rabbit (see Thomas Harriot Galaxy Picture Library: 01628 521338; The Galileo Project: Thomas Harriot's Moon Drawings).

   Galileo's Moon maps show all these things too, of course (see The Galileo Project: The Moon; file galileo_moon_map.html).

4. Another important example of Harriot's unpublished works is his discovery of Snell's law (AKA the law of refraction) which he discovered in 1602 long before Willebrord Snellius (1580--1626) in 1621.

   Actually, Ibn Sahl (c.940--c.1000) discovered Snell's law much earlier and reported it in his manuscript On Burning Mirrors and Lenses (984)---but this was largely unknown until modern history of science research---maybe only in 1990 (see Wikipedia: Snell's law: History).

   Another actually is that the effective discovery of Snell's law was by Rene Descartes (1596--1650) in 1637. It is an effective discovery because he published it, and so people knew of it. Snellius got credit by good luck.