APPENDIX A A. 315 



Statics (o-rard?, remaining still). A branch of mechanics. That 

 branch of mechanics which considers the relations of forces which 

 act upon bodies at rest. 



Dynamics (Swa/ik, force or power). A branch of mechanics. 

 That branch which treats of the action of force in producing motion. 

 It is divided into two parts : 



Kinematics (uvelv, to move, to put in motion), which investigates 

 the circumstances of mere motion without reference to the bodies 

 moved, the forces producing motion, or to the forces called into 

 action by the motion ; 



Kinetics (welv), which investigates the nature and relation of the 

 forces which produce motion. 



Astronomy (farrpov, a star, i>o/*os, law) is the science of celestial 

 bodies. It includes every notion relating to planets and stars, to 

 their motions, distribution in space, their respective distances, their 

 physical constitution, and the reciprocal influence which they 

 exercise upon one another. 



The utility of astronomy, apart from its sublimity, gives it the 

 first rank among sciences. Astronomy, in the first place, serves to 

 measure time and fix chronological periods ; secondly, to determine 

 the different points on the surface of the globe ; thirdly, to regulate 

 navigation. 



This science although it degenerated into astrology at times, 

 and thus hardly deserved the name of science is one of the most 

 ancient ; but it was in modern times only that a real knowledge of 

 the constitution of the world was attained. 



Geography (yy, earth, ypa$e/, to describe) is the description of the 

 earth ; it embraces everything relating to the state or condition 

 (either natural or artificial) of the globe which we inhabit. It is 

 divided into three branches : 



(1) Mathematical geography, the object of which is to determine 

 the shape and dimensions of the earth, its relation to the heavenly 

 bodies, the relative positions and distances of places on its surface, 

 and the representation of the earth upon globes or maps ; 



(2) Physical geography, the object of which is the description of 

 the principal features of the globe's surface (seas, continents, islands, 

 mountains, valleys, rivers) with their extent and configuration. 

 Meteorology and climatology belong to this branch, and hence, also, 

 the distribution of plants and animals in every part of the earth ; 



