Effects of the Orlicular and Rotary Motions of tlie Earth. 4 1 1 



tary motion, in relation to that of the orbicular motion. It will 

 likewise be found that periodical fluctuations in the weight, and 

 deflections of the atmosphere and other fluids, may be traced to 

 periodical variations in the relative direction? of the mechanical 

 forces, as in the tides, monsoons, trade-winds, &c. 



To extend these principles to the solution of the phsenomena 

 of Nature, and to deduce from them all the results of which they 

 are susceptible, would be, in regard at least to nomenclature, to 

 remodel the " Principia" of Newton, and to arrange a new sy- 

 stem of physics. 



Nevertheless, I feel it proper to state, that these demonstra- 

 tions of the true and necessary causes of the phaenomena hitherto 

 ascribed to an unknown power, called by the name of Gravitation, 

 merely fill some important connecting terms in the series of me- 

 chanical causes ascertained by modern philosophy; while they 

 disturb none of the known relations of bodies, as determined by 

 experiment and observation, or by the geometricul and analytical 

 investigations of Galileo, Kepler, Descartes, Newton, Euler, La 

 Grange, Herschol, or Laplace. 

 A Summary of these doctrines may, perhaps,^ withotit material 



error, or omission, be expressed in the following paragraphs : 



1. That bodies moved in the annual orbit of any planet, ac- 

 quire a momentum in the direction of the increments of that 

 orbit superior to the influence of any other permanent force 

 which is communicated to them. 



2. That all variations in the direction of this orbicular motio'i. 

 are effected by deflections of that paramount motion, either isy 

 the rotary diurnal motion, or by some muscular, mechanical, ov 

 chemical force. 



S. That the resistance which bodies exhibit ni being lifted, or 

 thrown, or in any way turned into any new direction, is the mea- 

 .nire of their weight, which is as their quantity of matter, be- 

 cause it arises from a velocity common to the terrestrial system 

 in tiie direction of the orbit. 



4. That the phaenomcna of falling bodies are produced by the 

 deflection of the circular rotary motion from the comparatively 

 straight line of the orbicular motion. 



5. That every body which has had any new direction of force 

 given to it, is nevertheless subject to the permanent influence of 

 the pre-existing orbicular and rotary forces in the lines of their 

 direction, and the resulting line of motion is the effect of all the 

 operative forces. 



6. That the phaenomenon of the ascent and descent ot bodiei 

 is also influenced by the resistanceof the medium through which 

 its novel direction of motion has forced it to proceed. 



7. The force with which the deflection by the rotary motion 



