XXXVI in the fourteenth rank of prerogative instance we will place the  instance of the cross borrow our metaphor from the cross erect where two road  meet to point out the different direction we be wont also to call they  decisive and judicial instance and in some case instance of the oracle and of  command their nature be as follow when in investigate any nature the  understanding be as it be balance and uncertain to which of two or more nature  the cause of the require nature shall be assign on account of the frequent and  usual concurrence of several nature the instance of the cross show that the  union of one nature with the require nature be firm and indissoluble while  that of the other be unsteady and separable by which mean the question be  decide and the first be receive as the cause while the other be dismiss and  reject such instance therefore afford great light and be of great weight so  that the course of interpretation sometime terminate and be complete in they  sometime however they be find among the instance already observe but they be  general new be express and purposely seek for and apply and bring to light  only by attentive and active diligence for example let the require nature be  the flow and ebb of the sea which be repeat twice a day at interval of six  hour between each advance and retreat with some little difference agree with  the motion of the moon we have here the follow crossway this motion must be  occasion either by the advance and the retire of the sea like water shake in a  basin which leave one side while it wash the other or by the rise of the sea  from the bottom and its again subside like boil water but a doubt arise to  which of these cause we shall assign the flow and ebb if the first assertion  be admit it follow that when there be a flood on one side there must at the  same time be a ebb on another and the question therefore be reduce to this now  acosta and some other after a diligent inquiry have observe that the flood  tide take place on the coast of Florida and the opposite coast of Spain and  Africa at the same time as do also the ebb and that there be not on the  contrary a flood tide at Florida when there be a ebb on the coast of Spain and  Africa yet if one consider the subject attentive this do not prove the  necessity of a rise motion nor refute the notion of a progressive motion for  the motion may be progressive and yet inundate the opposite shore of a channel  at the same time as if the water be force and drive together from some other  quarter for instance which take place in river for they flow and ebb towards  each bank at the same time yet their motion be clear progressive be that of  the water from the sea enter their mouth so it may happen that the water come  in a vast body from the eastern Indian ocean be drive together and force into  the channel of the Atlantic and therefore inundate both coast at once we must  inquire therefore if there be any other channel by which the water can at the  same time sink and ebb and the southern ocean at once suggest itself which be  not less than the Atlantic but rather broad and more extensive than be  requisite for this effect we at length arrive then at a instance of the cross  which be this if it be positive discover that when the flood set in towards  the opposite coast of Florida and Spain in the Atlantic there be at the same  time a flood tide on the coast of Peru and the back part of china in the  southern ocean then assure from this decisive instance we must reject the  assertion that the flood and ebb of the sea about which we inquire take place  by progressive motion for no other sea or place be leave where there can be a  ebb but this may most easy be learned by inquire of the inhabitant of Panama  and Lima where the two ocean be separate by a narrow isthmus whether the flood  and ebb take place on the opposite side of the isthmus at the same time or the  reverse this decision or rejection appear certain if it be grant that the  earth be fix but if the earth revolve it may perhaps happen that from the  unequal revolution as regard velocity of the earth and the water of the sea  there may be a violent force of the water into a mass from the flood and a  subsequent relaxation of they when they can no long bear the accumulation from  the ebb a separate inquiry must be make into this Even with this hypothesis  however it remain equal true that there must be a ebb somewhere at the same  time that there be a flood in another quarter again let the require nature be  the latter of the two motion we have suppose namely that of a rise and subside  motion if it shall happen that upon diligent examination the progressive  motion be reject we have then three way before we with regard to this nature  the motion by which the water raise themselves and again fall back in the  flood and ebb without the addition of any other water roll towards they must  take place in one of the three follow way either the supply of water emanate  from the interior of the earth and return back again or there be real no great  quantity of water but the same water without any augmentation of its quantity  be extend or rarefy so as to occupy a great space and dimension and again  contract itself or there be neither a additional supply nor any extension but  the same water with regard to quantity density or rarity raise themselves and  fall from sympathy by some magnetic power attract and call they up as it be  from above let we then pass over the first two motion reduce the investigation  to the last and inquire if there be any such elevation of the water by  sympathy or a magnetic force and it be evident in the first place that the  whole mass of water be place in the trench or cavity of the sea can be raise  at once because there will not be enough to cover the bottom so that if there  be any tendency of this kind in the water to raise itself yet it will be  interrupt and check by the cohesion of thing or as the common expression be  that there may be no vacuum the water therefore must rise on one side and for  that reason be diminish and ebb on another but it will again necessary follow  that the magnetic power not be able to operate on the whole operate most  intense on the centre so as to raise the water there which when thus raise  successive desert and abandon the side we at length arrive then at a instance  of the cross which be this if it be find that during the ebb the surface of  the water at sea be more curve and round from the water rise in the middle and  sink at the side or coast and if during a flood it be more even and level from  the water return to their former position then assure by this decisive  instance the raise of they by a magnetic force can be admit if otherwise it  must be entire reject it be not difficult to make the experiment by sound in  strait whether the sea be deep towards the middle in ebb than in flood but it  must be observe if this be the case that contrary to common opinion the water  rise in ebb and only return to their former position in flood so as to bath  and inundate the coast again let the require nature be the spontaneous motion  of revolution and particular whether the diurnal motion by which the sun and  star appear to we to rise and set be a real motion of revolution in the  heavenly body or only apparent in they and real in the earth there may be a  instance of the cross of the follow nature if there be discover any motion in  the ocean from east to west though very languid and weak and if the same  motion be discover rather more swift in the air particular within the tropics  where it be more perceptible from the circle be great if it be discover also  in the low comet and be already quick and powerful in they if it be find also  in the planet but so temper and regulate as to be slow in those near the earth  and quick in those at the great distance be quick of all in the heaven then  the diurnal motion shall certain be consider as real in the heaven and that of  the earth must be reject for it will be evident that the motion from east to  west be part of the system of the world and universal since it be most rapid  in the height of the heaven and gradual grow weak till it stop and be  extinguish in rest at the earth again let the require nature be that other  motion of revolution so celebrate among astronomer which be contrary to the  diurnal namely from west to east and which the ancient astronomer assign to  the planet and even to the starry sphere but Copernicus and his follower to  the earth also and let it be examine whether any such motion be find in nature  or it be rather a fiction and hypothesis for abridge and facilitate  calculation and for promote that fine notion of effect the heavenly motion by  perfect circle for there be nothing which prove such a motion in heavenly  object to be true and real either in a planet not return in its diurnal motion  to the same point of the starry sphere or in the pole of the zodiac be  different from that of the world which two circumstance have occasion this  notion for the first phenomenon be well account for by the sphere overtake or  fall behind each other and the second by spiral line so that the inaccuracy of  the return and declination to the tropics may be rather modification of the  one diurnal motion than contrary motion or about different pole and it be most  certain if we consider ourselves for a moment as part of the vulgar set aside  the fiction of astronomer and the school who be wont undeserving to attack the  sense in many respect and to affect obscurity that the apparent motion be such  as we have say a model of which we have sometime cause to be represent by wire  in a sort of a machine we may take the follow instance of the cross upon this  subject if it be find in any history worthy of credit that there have exist  any comet high or low which have not revolve in manifest harmony however  irregular with the diurnal motion then we may decide so far as to allow such a  motion to be possible in nature but if nothing of the sort be find it must be  suspect and recourse must be have to other instance of the cross again let the  require nature be weight or gravity heavy and ponderous body must either of  their own nature tend towards the centre of the earth by their peculiar  formation or must be attract and hurry by the corporeal mass of the earth  itself as be a assemblage of similar body and be draw to it by sympathy but if  the latter be the cause it follow that the near body approach to the earth the  more powerful and rapid they must be bear towards it and the further they be  distant the more faint and slow as be the case in magnetic attraction and that  this must happen within a give distance so that if they be separate at such a  distance from the earth that the power of the earth can act upon they they  will remain suspend like the earth and not fall at all the follow instance of  the cross may be adopt take a clock move by leaden weight and another by a  spring and let they be set well together so that one be neither quick nor slow  than the other then let the clock move by weight be place on the top of a very  high church and the other be keep below and let it be well observe if the  former move slow than it do from the diminish power of the weight let the same  experiment be make at the bottom of i work to a considerable depth in order to  see whether the clock move more quick from the increase power of the weight  but if this power be find to diminish at a height and to increase in  subterraneous place the attraction of the corporeal mass of the earth may be  take as the cause of weight again let the require nature be the polarity of  the steel needle when touch with the magnet we have these two way with regard  to this nature either the touch of the magnet must communicate polarity to the  steel towards the north and south or else it may only excite and prepare it  while the actual motion be occasion by the presence of the earth which Gilbert  consider to be the case and endeavour to prove with so much labour the  particular he have inquire into with such ingenious zeal amount to this a iron  bolt place for a long time towards the north and south acquire polarity from  this habit without the touch of the magnet as if the earth itself operate but  weak from its distance for the surface or outer crust of the earth do not in  his opinion possess the magnetic power yet by long continue motion can supply  the place of the magnet excite the iron and convert and change it when excite  iron at a read or white heat when quench in a direction parallel to the north  and south also acquire polarity without the touch of the magnet as if the part  of iron be put in motion by ignition and afterward recover themselves be at  the moment of be quench more susceptible and sensitive of the power emanate  from the earth than at other time and therefore as it be excite but these  point though well observe do not complete prove his assertion a instance of  the cross on this point may be as follow let a small magnetic globe be take  and its pole mark and place towards the east and west not towards the north  and south and let it continue thus then let a untouched needle be place over  it and suffer to remain so for six or seven day now the needle for this be not  dispute while it remain over the magnet will leave the pole of the world and  turn to those of the magnet and therefore as long as it remain in the above  position will turn to the east and west but if the needle when remove from the  magnet and place upon a pivot be find immediate to turn to the north and south  or even by degree to return thither then the presence of the earth must be  consider as the cause but if it remain turn as at first towards the east and  west or lose its polarity then that cause must be suspect and further inquiry  make again let the require nature be the corporeal substance of the moon  whether it be rare fiery and aerial as most of the ancient philosopher have  think or solid and dense as Gilbert and many of the modern with some of the  ancient hold the reason for this latter opinion be ground chief upon this that  the moon reflect the sun ray and that light do not appear capable of be  reflect except by solid the instance of the cross will therefore if any be  such as to exhibit reflection by a rare body such as flame if it be but  sufficient dense now certain one of the reason of twilight be the reflection  of the ray of the sun by the upper part of the atmosphere we see the sun ray  also reflect on fine evening by streak of moist cloud with a splendour not  less but perhaps more bright and glorious than that reflect from the body of  the moon and yet it be not clear that those cloud have from into a dense body  of water we see also that the dark air behind the window at night reflect the  light of a candle in the same manner as a dense body will do the experiment  shall also be make of cause the sun ray to fall through a hold upon some dark  and bluish flame the unconfined ray of the sun when fall on faint flame do  certain appear to deaden they and render they more like white smoke than flame  these be the only instance which occur at present of the nature of those of  the cross and better perhaps can be find but it must always be observe that  reflection be not to be expect from flame unless it be of some depth for  otherwise it become near transparent this at least may be consider certain  that light be always either receive and transmit or reflect by a even surface  again let the require nature be the motion of projectile such as dart arrow  and ball through the air the school in its usual manner treat this very  careless consider it enough to distinguish it by the name of violent motion  from that which they term natural and as far as regard the first percussion or  impulse satisfy itself by its axiom that two body can exist in one place or  there will be a penetration of dimension with regard to this nature we have  these two crossway the motion must arise either from the air carry the project  body and collect behind it like a stream behind boat or the wind behind straw  or from the part of the body itself not support the impression but push  themselves forward in succession to ease it fracastorius and near all those  who have enter into any refine inquiry upon the subject adopt the first nor  can it be doubt that the air have some effect yet the other motion be without  doubt real as be clear from a vast number of experiment among other we may  take this instance of the cross namely that a thin plate or wire of iron  rather stiff or even a reed or pen split in two when draw up and bend between  the finger and thumb will leap forward for it be clear that this can be  attribute to the air be be collect behind the body because the source of  motion be in the centre of the plate or pen and not in its extremity again let  the require nature be the rapid and powerful motion of the explosion of  gunpowder by which such vast mass be upheave and such weight discharge as we  observe in large i and mortar there be two crossway before we with regard to  this nature this motion be excite either by the mere effort of the body expand  itself when inflame or by the assist effort of the crude spirit which escape  rapid from fire and burst violent from the surround flame as from a prison the  school however and common opinion only consider the first effort for man think  that they be great philosopher when they assert that flame from the from of  the element be endow with a kind of necessity of occupy a great space than the  same body have occupy when in the from of powder and that thence proceed the  motion in question in the meantime they do not observe that although this may  be true on the supposition of flame be generate yet the generation may be  impede by a weight of sufficient force to compress and suffocate it so that no  such necessity exist as they assert they be right indeed in imagine that the  expansion and the consequent emission or removal of the oppose body be  necessary if flame be once generate but such a necessity be avoid if the solid  oppose mass suppress the flame before it be generate and we in fact see that  flame especial at the moment of its generation be mild and gentle and require  a hollow space where it can play and try its force the great violence of the  effect therefore can be attribute to this cause but the truth be that the  generation of these explode flame and fiery blast arise from the conflict of  two body of a decide opposite nature the one very inflammable as be the  sulphur the other have a antipathy to flame namely the crude spirit of the  nitre so that a extraordinary conflict take place while the sulphur be become  inflame as far as it can for the three body the willow charcoal mere  incorporate and convenient unite the two other and the spirit of nitre be  escape as far also as it can and at the same time expand itself for air and  all crude substance and water be expand by heat fan thus in every direction  the flame of the sulphur by its escape and violence just as if by invisible  bellows two kind of instance of the cross may here be use the one of very  inflammable substance such as sulphur and camphor naphtha and the like and  their compound which take fire more ready and easy than gunpowder if leave to  themselves and this show that the effort to catch fire do not of itself  produce such a prodigious effect the other of substance which avoid and repel  flame such as all salt for we see that when they be cast into the fire the  aqueous spirit escape with a crackle noise before flame be produce which also  happen in a less degree in stiff leave from the escape of the aqueous part  before the oily part have catch fire this be more particular observe in  quicksilver which be not improper call mineral water and which without any  inflammation near equal the force of gunpowder by simple explosion and  expansion and be say when mix with gunpowder to increase its force again let  the require nature be the transitory nature of flame and its momentaneous  extinction for to we the nature of flame do not appear to be fix or settle but  to be generate from moment to moment and to be every instant extinguish it be  clear that those flame which continue and last do not owe their continuance to  the same mass of flame but to a continue succession of new flame regular  generate and that the same identical flame do not continue this be easy show  by remove the food or source of the flame when it at once go out we have the  two follow crossway with regard to this nature this momentary nature either  arise from the cessation of the cause which first produce it as in light sound  and violent motion as they be term or flame may be capable by its own nature  of duration but be subject to some violence from the contrary nature which  surround it and be destroy we may therefore adopt the follow instance of the  cross we see to what a height the flame rise in great conflagration for as the  base of the flame become more extensive its vertex be more lofty it appear  then that the commencement of the extinction take place at the side where the  flame be compress by the air and be ill at ease but the centre of the flame  which be untouched by the air and surround by flame continue the same and be  not extinguish until compress by degree by the air attack it from the side all  flame therefore be pyramidal have its base near the source and its vertex  point from its be resist by the air and not supply from the source on the  contrary the smoke which be narrow at the base expand in its ascent and  resemble a invert pyramid because the air admit the smoke but compress the  flame for let no one dream that the light flame be air since they be clear  heterogeneous the instance of the cross will be more accurate if the  experiment can be make by flame of different colour take therefore a small  metal sconce and place a light taper in it then put it in a basin and pour a  small quantity of spirit of wine round the sconce so as not to reach its edge  and light the spirit now the flame of the spirit will be blue and that of the  taper yellow observe therefore whether the latter which can easy be  distinguish from the former by its colour for flame do not mix immediate as  liquid do continue pyramidal or tend more to a globular figure since there be  nothing to destroy or compress it if the latter result be observe it must be  consider as settle that flame continue positive the same while enclose within  another flame and not expose to the resist force of the air let this suffice  for the instance of the cross we have dwell the long upon they in order  gradual to teach and accustom mankind to judge of nature by these instance and  enlighten experiment and not by probable reason