CHRONOMETER 



1372 



CHRYSANTHEMUM 



The Greeks reckoned time by the four-year 

 intervals between the Olympic games, which 

 were known as Olympiads. They began their 

 era from a date which corresponds to 776 B.C. 

 The Roman era begins with the founding of the 

 city of Rome, 753 B. c. being the date generally 

 accepted. Another important era is the Mo- 

 hammedan, dating from Mohammed's flight 

 from Mecca in A. D. 622 (see HEGIRA). The 

 American and European year 1917 is therefore 

 the Mohammedan year 1295. See CALENDAR; 

 YEAR. * 



CHRONOMETER, kro nom'e ter, in a general 

 sense, is any instrument that measures and 

 records time. Thus, a clock, a wetch, a sun- 

 dial or any other device that does this is a 

 chronometer. In a specific sense, a chronom- 

 eter is an instrument made for very accurate 

 and minute measurements of time. The one 

 most widely known is the marine chronometer, 

 which determines time in connection with find- 

 ing longitude at sea. For this purpose it is 

 set at the time of some first, or prime, merid- 

 ian. Greenwich time is used by American and 

 British ships; that of Paris, by the French, 

 and that of Berlin, by the Germans. The 

 mechanism of these instruments is very delicate 

 and easily affected by outside influences; they 

 must be kept away from the magnetic in- 

 fluence of compasses and from the vibrations 

 of the ship. These chronometers are hung in 

 their cases on gimbals so they may always be 

 in a horizontal position. A pocket chronom- 

 eter, which is used for railroad and racing 

 purposes, looks like an ordinary watch, but 

 is somewhat larger. It registers very small 

 fractions of time. 



CHRYSALIS, kris'alis, the resting state of 

 butterflies in the process of development, when 



FORMS OF CHRYSALIDS 

 (a) Sphinx moth; (ft) monarch butterfly; 

 (c) mosquito. 



they cease to be larvae (young), and before 

 they reach their winged, or perfect state. This 

 state in the lives of moths and many other 



insects is called the pupa stage. From a life 

 of motion and plenty to eat, the worm or 

 caterpillar builds itself into a shell-like house, 

 or silky cocoon. Attached to a leaf, twig or 

 fence, without food and merely breathing, it 

 rests and develops until ready to burst forth 

 a beautiful, quivering creature of the air, a 

 perfect butterfly. The pupa, or chrysalis, 

 usually takes the color of the object te which 

 it is attached. See BUTTERFLY. 



CHRYSANTHEMUM, kris an' the mum, a 

 stately, free-blooming autumn flower, the na- 

 tional flower and imperial emblem of Japan. 

 The story of the chrysanthemum is most inter- 

 esting. In its natural state it is much Jikc 



CHRYSANTHEMUM 



the aster coarse-leaved, with rather common 

 looking flowers, the ox-eye daisy and the corn 

 marigold being two species. But as a result 

 of care and cultivation the chrysanthemums 

 of the gardens and hothouses to-day are gor- 

 geous offspring of Chinese and Japanese vari- 

 eties, with leaves pale green or dusty silver, 

 and large, globelike, ragged-blossomed flowers 

 of many forms and colors. Every year when 

 the gray days come and other flowers have 

 faded, in garden spots or florists' windows or 

 under the glass of greenhouses the chrysan- 

 themum, the "golden flower," affords a wealth 

 of brilliant hues. 



In the Imperial Gardens of Japan originated 

 the custom of "chrysanthemum shows." Now 

 each year in many countries, for several weeks 

 at a time, rich and poor alike can feast on 

 the sight of chrysanthemums white or yellow, 

 pink or purplish-rose and red, quilled or 



