RAINBOW 



4923 



RAINIER 



Life Follows Rain. Practically all forms of 

 plant life depend on rain. Where the rainfall 

 is abundant, the land is covered with vegeta- 

 tion ; where there is no rain the land is barren. 

 And ^t follows, logically, that where plant life 

 is abundant, there animal life is abundant. It 

 is one of the triumphs of civilization that it 

 can modify this law, for the deserts of the 

 world are being conquered to-day as never 

 before and made into the garden spots of the 

 earth through irrigation. A.C. 



Consult Henry's "Rainfall in the United States," 

 nther Bureau Bulletin D. 



ItHnted Subject*. The reader is referred to 

 the following articles in these volumes in con- 

 nection with this discussion of rain : 

 Climate, subhead Rain- Humidity 



fall 

 Cloud 

 Desert 

 Dew 



Atmospheric 

 Evaporation 

 Flood 

 Fog 

 Hail 



Irrigation 



Lightning 



Meteorology 



Rainbow 



Rain Gauge 



Snow 



Storms 



Weather Bureau 



Wind 



RAINBOW, rain' bo. Often when the sun 

 >hines and there is a shower of rain we see in 

 that part of the heavens opposite the sun an 

 arch of beautiful colors. If the rain is of 

 sufficient extent the bow spans the entire arc 

 of the sky and its two ends seem to rest on 

 the earth below. The cause of this interesting 

 natural phenomenon is the reflection and re- 

 fraction of the sun's rays as they fall on drops 

 of rain. Sunlight, or white light, we know, is 

 a combination of seven colors violet, indigo, 

 blue, green, yellow, orange, red (see LIGHT, 

 HiMiead The Spectrum; COLOR). As a ray from 

 the sun passes into a drop of rain the latin 

 acts like a tiny prism; the ray is bent, or re- 

 fracted, as it enters the drop, and is dispersed 

 or separated into different colors. On striking 

 the mn.-r surface of the drop it is reflected, or 

 turned back, and on leaving flu drop is further 

 refracted and dispersed. What we see in the 

 heavens is a beautiful natural spectrum, pro- 

 duced by successive drops. Each color is 

 .exJ by rays that reach the eye at a certain 

 and--, ;ui.l the angle for a particular color n> 



A complete bow shows two bands of colors, 



:m.l hrichti r on.- I., inu call. .1 tin- 

 primary bow, and the outer and less distinct. 

 condary bow. Th y bow ho- 



n the outside and the violet on tl 



while in the secondary bow the 

 colors are reversed. In the secondary 



c 



there are two reflections within the drop. The 

 higher the sun, the lower the bow, and if the 

 sun is higher than forty degrees, no bow is 

 visible. When the sun is near the horizon, an 

 observer on a high mountain or in a balloon 

 might see the whole circle of the rainbow. 

 Rainbows are often observed in the spray that 

 flies from a cataract. Very beautiful ones may 

 be seen on sunny days at Niagara Falls. 



RAIN GAUGE, gayj, an instrument for col- 

 lecting and measuring rain. There are numer- 

 ous patterns of these instruments, but the sim- 

 ple rain guage in use by the United States 

 Weather Bureau is the most easily understood 

 and operated. 

 In shape it re- 

 sembles a cylin- 

 drical pill box 

 with a removable 

 cover (see draw- 

 ing). Inside is a 

 smaller tube (6) 

 which widens 

 into a funnel (a) 

 at the top. As 

 the area of the 

 fnnnel is ten 

 times that of the 

 tube, one -tenth 

 of an inch of RAIN GAUGE 



water falling into ^Explanation appears In the 

 a fills & to a 



depth of one inch. When the tube is full the 

 surplus water overflows into the reservoir (r). 

 With a rule divided into inches and tenths of 

 inches instead of halves, quarters and eighths, 

 tin- water in the tube b is measured. In case 

 the fall of rain is so heavy that the water over- 

 flows into r. the water in 6 is poured out I 

 measuring, and that in c is poured into the tube 

 and measured. The sum of the two measure- 

 ments is the amount of rainfall. The gauge 

 should be set far enough away from buildings, 

 or other tall objects to prevent any ob- 

 Mmction of the rain. 



A gauge placed near the ground shows a 

 greater fall of rain than one at a height, be- 

 cause th< < i rope passing a greater distance 

 through tin- air collect more moisture. There- 

 fore, if the rainfall at two places is to be com- 

 pared, the gauges must be placed at similar 



heights. 



RAINIER, ran. \T, a peak of vol- 



thfl highest in the state of Wash- 

 ington, called Mount Rainier in a good-nar. 



< i rivalry In the residents of Seattle and 



