This appendix is an adaptation of the “Solar History Timeline,” courtesy of the U.S. Department of Energy.

1. Seventh Century BC. A magnifying glass is used to concentrate the sun's rays on a fuel and light a fire for light, warmth, and cooking.

2. Third Century BC. Greeks and Romans use mirrors to light torches for religious purposes.

3. Second Century BC. As early as 212 BC, the Greek scientist Archimedes makes use of the reflective properties of bronze shields to focus sunlight and set fire to Rome's wooden ships, which were besieging Syracuse. Although there is no proof that this actually happened, the Greek navy re-created the experiment in 1973 and successfully set fire to a wooden boat 50 m away.

4. AD 20. The Chinese report using mirrors to light torches for religious purposes.

5. First to the Fourth Century. In the first to the fourth centuries, Roman bath houses are built with large, south-facing windows to let in the sun's warmth.

6. Sixth Century. Sunrooms on houses and public buildings are so common that the Justinian Code establishes “sun rights” to ensure that a building has access to the sun.

7. Thirteenth Century. In North America, the ancestors of Pueblo people, known as Anasazi build south-facing cliff dwellings that capture the warmth of the winter sun.

8. 1767. Swiss scientist Horace de Saussure is credited with building the world's first solar collector, later used by Sir John Herschel to cook food during his South African expedition in the 1830s.

9. 1816. On September 27, 1816, Robert Stirling applies for a patent for his economiser, a solar thermal electric technology that concentrates the sun's thermal energy to produce electric power.

10. 1839. French scientist Edmond Becquerel discovers the photovoltaic effect while experimenting with an electrolytic cell made up of two metal electrodes placed in an electricity-conducting solution; the electricity generation increases when exposed to light.

11. 1860s. French mathematician August Mouchet proposes an idea for solar-powered steam engines. In the next two decades, he and his assistant, Abel Pifre, will construct the first solar-powered engines for a variety of uses. The engines are the predecessors of modern parabolic dish collectors.

12. 1873. Willoughby Smith discovers the photoconductivity of selenium.

13. 1876. William Grylls Adams and Richard Evans Day discover that selenium produces electricity when exposed to light.