from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A unit equal to one gram calorie per square centimeter of irradiated surface, used to measure solar radiation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A unit of heat transmission in the CGS system of units. It is equivalent to 41,840 J/m² in SI units. Symbol: Ly.
After Samuel Pierpoint Langley.(American Heritage® Dictionary of the English Language, Fourth Edition)