154 Oft he Advancement of Learning. L i b. V. 



and prefently be fet dovvn^and pradtifed in fome work.But let men know 

 for certain. That fulid and true Arts of Invention do Jldoot up, and come 

 to maturity with the Inventions themfelves : So as vchen a man firjl en- 

 ters upon thefearch of a knowledge, he may have many profitable Precepts of 

 Invention ; hut after he hath made farther progress in the kporoledge it 

 felt, he m zy, and mujl excogitate new Precepts of Invention, which may^ 

 lead him more profperoiifly to further Difcoveries. For this kind of pur- 

 fuit is like a going upon a plain and open Champion ; for after we have 

 gone a part of the way , we have not only gained this, that we are 

 now nearer to our journeys end ; but we gain the better fight of that 

 part of the way, which remains. So every degree oi proceeding in Sci- 

 ences, having part over that which is left behind, gives a better pro(pe(ft 

 to that which follows : And becaufe we fet down this part of Topick 

 as Deficient^ we will annex an example thereof. 



L 



III. A particular Topick., ov the Articles of Enquiry 

 cle GK AVI e^ L E V I. 



Et it he enquired Vfhzx. Bodies thofe are which are fufceptible of the 

 Motion nf Gravity, what of Levity^ and whether there be any of a 

 middle and indifferent Nature ? 



2. After an ahfohtte Inquiry de Gravi d^ Levi -, proceed to comparative 

 Inquiry j as o( Ponderous Bodies, which doth weigh more, which le(s, in 

 the fame demenfion ? fo oi^ Light Bodies, which are more fpeedily car- 

 ried upward, which moreflowly > 



5. Let it be enquired, what the ^ranfum of a Body may contribute^ 

 andefFedt towards the Motion of Gravity. But this, at firft fight, may 

 feem a fuperflupus Inquiry, becaufe the computation of motion mufl 

 foWovf the computation of quantity : But the matter is othervvife ; for 

 although the quantity in the fcales do compenfate the weight of the Bo- 

 dy it felf, (the force of the Body every way meeting by repercuffion , 

 or by refiftance, of the Bafins, or of the Beam ) yet where there is but 

 fmallrefiflance (as in the falling down of a Body through the Air) the 

 quantity of a Body little avails to the incitation of the defccnt j feeing 

 two Balls of Lead, one oi twenty, the other of one pound weight, fall to 

 the earth almoft in an equal fpace of time. 



4. Let it be inquired, whether the Quantity of a Body may be fb 

 increafed , as that the Motion oj Gravity may be utterly depofed and 

 caft off 5 as in the Globe of the earth, which is penfil, and falls not } 

 Whether may there be other mafiive fubflances, fb great.as may fuftaia 

 V. Di- themfelves ? For Local Defcent to the Centre of the Earth, is ameerfi'&i- 

 on--i and every great Mafs abhorrs all Local Motion, unlcfs it beover*" 

 rul'd by another more predominant Appetite, 



5 Let it be inquired, what the refijiance of a Body interpofing, or in- 

 countring may do, or aftuate towards the managing of the Amotion of 

 Gravity : For a Body defcending, either penetrates and cutteth the Bo- 

 dy occurrenti or is arrcfted by it ; \^ xt penetrates , then there \s pene- 

 tration ; or with weaker refiftence, as in Air, or with more ftrong, as 

 in Water ; If it hejiiid, it is ftaid either by a refiftance unequal, where 

 there is a Pregravation ^ as if Wood fhould be pat upon Wax 5 or e- 

 qual, as if Water Ihould be put upon Water, or Wood upon Wood of 



the 



