156 BACON 



prospect of those that remain ; and as we report this particular 

 topical invention deficient, we think proper to give an example 

 of it in the subject of gravity and levity. 



1. Let inquiries be made what kind of bodies are susceptible 

 of the motion of gravity; what of levity; and if there be any 

 of a middle or neutral nature. 



2. After the simple inquiry of gravity and levity, proceed to a 

 comparative inquiry; viz., which heavy bodies weigh more, 

 and which less, in the same dimensions ; and of like ones, which 

 mount upwards the swifter, and which the slower. 



3. Inquire what effect the quantity of the body has in the mo- 

 tion of gravity. This at first sight may appear a needless in- 

 quiry, because motion may seem proportionable to quan- 

 tity; but the case is otherwise. For although in scales 

 quantity is equal to the gravity, yet where there is a small re- 

 sistance, as in the falling of bodies through the air, quantity 

 has but little force to quicken the descent ; but twenty pounds 

 of lead, and a single pound, fall nearly in the same time. 



4. Inquire whether the quantity of a body may be so in- 

 creased as that the motion of gravity shall be entirely lost, as 

 in the globe of the earth, which hangs pendulous without fall- 

 ing. Quaere, therefore, whether other masses may be so large 

 as to sustain themselves ? For that bodies should move to the 

 centre of the earth is a fiction ; and every mass of matter has an 

 aversion to local motion, till this be overcome by some stronger 

 impulse. 



5. Inquire into the effects and nature of resisting mediums, 

 as to their influencing the motion of gravity ; for a falling body 

 either penetrates and cuts through the body it meets in its way, 

 or else is stopped by it. If it pass through, there is a penetra- 

 tion, either with a small resistance, as in air, or with a greater, 

 as in water. If it be stopped, it is stopped by an unequal resist- 

 ance, where there is a preponderancy, as when wood is laid 

 upon wax ; or by an equal resistance, as when water is laid 

 upon water, or wood upon wood of the same kind ; which is 

 what the schools pretend, when they idly imagine that bodies 

 'do nof gravitate in their own places. And all these circum- 

 stances alter the motion of gravity ; for heavy bodies move after 

 one way in the balance, and after another in falling ; and, which 

 may seem strange, after one way in a balance suspended in air, 

 and after another in a balance plunged in water ; after one way 



