" I took a number of little square pieces of broadcloth from a tailor's 

 pattern-card, of various colors. They were black, deep blue, lighter blue, 

 green, purple, red, yellow, white, and other colors, or shades of color. I 

 laid them all out upon the snow on a bright, sunshiny morning. In a few 

 hours (I cannot now be exact as to the time), the black, being warmed 

 most by the sun, was sunk so low as to be below the stroke of the sun's 

 rays ; the dark blue almost as low, the lighter blue not quite so much as 

 the dark, the other colors less as they were lighter. The white remained 

 on the surface of the snow, not having entered it at all. 



" What signifies philosophy that does not apply to some use ? May 

 we not learn from hence that black clothes are not so fit to wear in a hot, 

 sunny climate or season as white ones ; because in such clothes the body 

 is more heated by the sun when we walk abroad, and are at the same time 

 heated by the exercise, which double heat is apt to bring on putrid, dan- 

 gerous fevers ? That soldiers and seamen, who must march and labor in 

 the sun, should, in the East or West Indies, have a uniform of white ? 

 That summer hats for men or women should be white, as repelling that 

 heat which gives headaches to so many, and to some the fatal stroke that 

 the French call coup de soleil ? That the ladies' summer hats, however, 

 should be lined with black, as not reverberating on their faces those rays 

 which are reflected upward from the earth or water ? That the putting 

 of a white cap of paper or linen within the crown of a black hat, as most 

 do, will not keep out the heat, though it would if placed without ? That 

 fruit walls being blacked may receive so much heat from the sun in the 

 daytime as to continue warm in some degree through the night, and 

 thereby preserve the fruit from frosts, or forward its growth with sun- 

 dry other particulars of greater or less importance that will occur from 

 time to time to attentive minds ? " 



BENJAMIN FRANKLIN, 

 Letter to Miss Mary Stevenson. 



