Philosophical Transactions/Volume 4/Number 48
PHILOSOPHICAL
TRANSACTIONS.
June 21. 1669.
The Contents.
Generatio
- Corporis Cylindroidis Hyperbolici, elaborandis Lentibus Hyperbolics accommodati, Auth. Christophoro Wren L L D. et Regiorum Ædificiorum Præfecto, nec non Soc. Regiæ Sodali.
SInt (in Fig. I.) Hyperbolæ oppositæ DB, EC, quarum Axis transversus est BC, Centrum A, et una ex Asymptotis GP; item per Centrum sit OM ducta ad angulos rectos ipsi BC. Quare si circumducantur Hyperbolæ circa Axin O M, manifestum est, ex ea revolutione generari corpus Cylindroides Hyperbolicum cujus Bases sectionesque Basi parabella sunt Circuli. Dico insuper, si idem corus secetur per Asymptotum G P, erit sectio Parallelogrammum.
Secetur per Axin transversum sectione circulari B N C; temp per O et M in Circules æquales & æqualiter a Centro distantes; item per Axin in figuram Geometricem cujus semissis est B D E C, in cujus plano erit Asymptotos G P , per quam ad rectos angulos planum B D E secctur in plano F H P; jungantur denique H O.
Quoniam Triangulum O G H est Rectangulum, Ergo Quadratum O H sive O D. minus Quadrato O G. est æquale Quadrato G H: et quoniam D O parallela est ipsi B A, et Asymptoton secat in G, erit (ex proprietatibut Hyperbolæ, quæ in Conicis demonstrantur) Quadratum O G und cum, Qudrato A B æquale Quadrato O D, b. e. Quadratum O D minus Quadrato O G æquale Quadrato A B sive Qaudrato A N. Ergo Quadratum G H æquale est, Quadrato A N. Quare G H et A N æquantur et sunt ad angulos rectos ipsi G A; idemque demonstratur de omnibus aliis sectionbus Basi parallelis. Quare Cylindroides Hyperbolicæ rite secatur per Asymptoton in Parallelogrammum. q. e. d.
Corallarium
Hinc patet, in superficie Cylindroidis, quamvis e duplici flexuræ constest, rectas nihilominus innumeras duci posse: Patet etiam, aliam esse hujus Corporis generationem, nimir. ex revolutione Parallelogrammi circa Axin manente angulo ad Axin æquali G A O, vel denique manente Linea Generatrice H R immobili, et massam volubilem formante aut secante. Et si acies Dolabri acutissima et rectissima ita disponatur ad Axin, sicut se habet Linea Generatrix, rotante interim Mamphure, manifestum est Torno tam accuratas posse elaborari Hyperbolas quam Circulos, cum nihil aliud requiratur ad formandam Cylindroidem quam ad Cylindrum, nisi quod in Cylindris acies dolabri est Axi parallela, hic cero inclinata. Itaque notandum est, pro Inclinatione Anguli G A O. variari speciem Hyperbolæ; adeoque facilius accommodatur ad datam Hyperbolam quam ut demonstratione opus habeat: At si manente angulo Generatrix magis ad Centrum accedat, exsurgit inde minor Hyperbola, sed priori prorsus similus.
Ex hoc Principio fabrifieri jam curavit Ingeniosisimus Author Machinam, simplicitate sua perquam commendabilem, cujus beneficio Lente elaborentur Hyperbolicæ. Illius descriptionem vna cum Icone brevi nos etiam edituros speramus.
Experiments
1. IN Birch-trees the Sap issues out of the least twiggs of Branches, and fibres of Roots, in proportion to their bigness.
2. In all Trees the Gravity promotes the Bleeding; so that from a Branch or Root, that bendes downward, there will issue a great deal more Sap, than from another of the same bigness in a more erect posture.
3. Branches and Young trees cut quite off when they are full of Sap, and held perpendicularly, will bleed; as we experimented in Willow, Birch, and Sycamore: And if you cutt off their tops, and invert them, they will bleed also at the little ends. Hence one may conjecture, that the narrowness of the pores is not the sole cause of the Ascent of the Sap; for, Water that hath ascended in the little glass-pipes, will not fall out againe by its own gravity, if the pipes be taken our of the water.
4. Roots of Birch and Sycamore cut asunder will bleed both ways, that is, from that part remaining to the Tree, and from the part separated; but a great deal faster from the part remaining to the Tree. But in a cold snowy day the Root of one Sycamore, we had bared, bled faster from the part separated, and ten times faster than it did in warm weather before.
5. In Birches the Sap does not issue out of the Barke, be it never so thick, bus as soone as ever you have cutt the Barke quite through, then it first begins to bleed.
6. The Bark being quite pared off above an hands breadth round, about severall Birches, did much abate the Bleeding of the Trees above the bared places, but did non quite stop it.
7. The Sap doth not only ascend between Bark and Tree, and in the prick't Circles between the severall coats of Wood; but also through the very Body of the Wood. For, several young Birches being nimbly cut off at one blow with a sharpe axe, and white paper immediately held hard upon the topp of the remaining trunk, we stuck downe pins in all the points of the paper as they appear'd wet: and at last, when the most of the paper became wet, taking it away, but leaving the pins sticking, we found them without any order, some in the Circles, and some in the Wood between. And yo confirm this further, we caused the Body of a Tree to be cut off aslope, and then cut the opposite side aslope likewise, till we brought the top to a narrow edge; ordering the matter so, that the whole edge consisted of part of a coat of Wood, and had nothing of a prick't Circle in it, which notwithstanding, the Sap ascended to the very top of this edge, and wetted a paper laid upon it.
8. To find out the motion of the Sap, whether it ascended only, or descended also; we bored a hole in a large Birch, out of which a drop fell every 4th or 5th pulse. Then, about a hands breadth just under the hole, we saw'd into the Body of the tree, deeper than the hole: whereupon the bleeding diminish'd about one half, and having. saw'd Iust above this hole to the same depth, the bleeding from the Hole ceas'd quite; and from the saw'd furrow below decreas'd about half: and it continued bleeding a great while after at both the saw'd furrows, the hole in the middle remaining dry. We repeated this with much the like success upon a Sycamore.
9. Some Trees of the same kind and age bleed at great deal faster and sooner than others; but always Old trees sooner and faster than Young.
10. A wound, made before the Sap rises, will bleed when it doth rise.
11. While we were making these Experiments, the weather changed from warme to very cold; whereupon the bleeding in the Birches, which begun to abate before, ceas'd quite. But all the Sycamore and Walnut-trees, we had wounded, bled abundantly; (some whereof before bled not at all, and those that did, did so but slowly;) and so continued night and day, when it froze to hard; that the Sap congealed as fast as it issued our. The Cold remitting, the Birches bled afresh, the Sycamores abated very much, and the Walnut-trees quite ceased.
12. We pierced two Sycamores on the North and Southsides, and both of them from equall incisions bled a greast deale faster from the North-sides, than the South, which is consonant to the preceding Experiment.
13. We set several Willows with the wrong ends downward; and cut off several Bryars, that had taken root at the small ends. This 29th of May the Willows have shot out Branches neare two foot long; and from the top of the Sets, which were a yard high, the Bryars have also grown backwards from that part, which we left remaining to the roots at the lesser ends; they have great leaves and are ready to flower.
An Extract of a Letter
SIr, having been lately in the Copper, Silver, and Gold-mines in Hungary, I hope ere long to give you a particular account thereof; presenting this in the mean time concerning Damps in these Mines; whereof I understand, that they happen in most of them, that are deep; and that they happen not only in the Cunicili or direct pall ages, where they walk on Horizontally (by these Mine-men call'd Stollen) but also in the Putei or Perpendicular Cutts or Descents (term'd Schachts by the same.) They are met with not only in places, where the Earth is full of Clay or the like substances, but also where it is Rocky: and one place they shew'd me in the Copper-mine at Hern-groundt, where there had been a very pernicious damp, and yet the Rock so hard, that it could not be broken by their Instruments; but the descent was all made by the means of Gun-powder, ram'd into long round holes in the Rock, and so blowne up. Another place they show'd me, where there is sometimes a damp, and sometimes clear weather. When there is much water in the Mine, so as to flop up the lower part of this passage, then the damp becomes discoverable, and commonly strong. I procured one to enter it, till his Lamp wear out 4. or 5 times, in the same manner as at Grotto del Cane in July.
Damps are not all of the same force, but some weaker, some stronger; some suffocate in a small space of time, others only render the Workemen faint, with no further hurt, except they continue long in the place. The Miners (who think themselves no Workmen, if they be not able to cure a Damp, or to cure the bad Weather, or make the Weather, as they term it) performe it by perflation by letting the Aire in and out, and causing as 'twere, a Circulation of it. In the Mine at Herrn-groundt they did cure a bad Damp by a great paire of Bellows, which were blown continually for many days. The ordinary remedy is by long Tubes, through which the Air continually passing, they are able to digg streight on for a long way without impediment in breathing. For some Cuniculi are 500. fathoms long; which will not seeme strange to any one that shall see the Mapp of the Copper-mine at Herrn-groundt or the Gold-mine at Chremnitz. And in the Silver-Trinity-mine by Schemnitz, I pass'd quite under a great Hill, and came out on the other side. At Windschach-mine by Schemnitz they show'd me the place. where 5. men and a Gentleman of quality were lost, for which reason they have now plac'd a Tube there. The like they place overall doores, and over all ways, where they digg right on for a great space, and have no passage through. At Chremnitz they told me, that 28. men had been killed at one time in 4. Cuniculi, 7. in each; and in the sinking of Leopold's-pitt, which is 150. fathoms deep, they were much troubled with damps, which they remedied in this manner.
They fixed a Tube to the side of the Schacht or Pitt, from the top to the bottom, and that not prouing sufficient, they forc'd down a broad flat board, which cover'd or stopp'd the Pitt or couched very near the sides of it, on all sides but where the Tube was; and so forc'd out all the Air in the pitt through, the Tube; which work they were forc'd often to repeat. And now they having divers other passages into it, the Air is good and sufficient; and I was drawn up through it without the least trouble in breathing.
But besides this mischief from poisonous Exhalations, Stagnation of the Air, or Water impregnated with minerall spirits, they sometimes perish by other ways. For there being in these Mines an incredible mass of wood to support the Pitts and the Horizontal passages, (the Putei and Cuniculi in all places but where 'tis Rocky, men are sometimes destroy'd by the wood set on fire. And in the Gold-mine at Chremnitz, the wood was once set on fire by the carelesness of a boy, and 50. Miners smothered thereby; who were all taken out but one, that was alterwards round to be dissolv'd by the Vitrioll water, nothing escaping either of flesh or bones but only some of his cloaths. I am &c.
- Vienna April. 20 1669.
A Chronological Accomptof the several Incendium's or Fires of Mount Ætna.
THe present Fire of Ætna, (whereof there was lately a Relation printed here in the Savoy) will make it appear not unseasonable to reflect back upon former Ages, and to collect from History the severall Eruptions hapned there, together with the times of them, and some observations recorded by Authors concerning the same.
To pass by what is related by Berosus, Orpheus and other less credible Authors, about the Eruptions oi this Mountain, both at the time of the ingress of the Ionian Colonies into Sicily, and that of the Argonautes (which latter was in the 12th Age before the Christian account;) we shall first take notice of that, which happen'd at the time of the Expedition of Æneas, who being terrified by the fire of this then burning Mountain, left that Island; whereof Virgil l. 3. Æneid. gives this notable description;
- Ignarique via, Cyclopum allabimur oris,
Portus ab acceßu ventorum immotus et ingens,
Ipse sed horrificis juxta tonat Ætna ruinis,
Interdumque etiam prorumpit ad æthera nubem
Turbine fumantem picco et candente favillá.
Attolitque globos flammarum, et sidera lambit.
- Interdum, scopulos, avulsaque viscera Montis
Erigit eructans, liquefactaque saxa sub auras
Cam gemitu glomerat fundoque exæstuat imo.
After this we find in Thucydides, that in the 76. Olympiad, which is about 476. before Christ, there was another Fire, and about 50. years after that, another.
Then, in the time of the Roman Consulls there haped four Eruptions of Ætna, recorded by Diodorus Siculus and Polybius
The next was in the time of Julius Cæsar, related by the said Diodorus to have been so feirce, that the Sea about Lipara (an island neere Sicily) by its fervent heat burnt the Ships, and kill'd all Fishes thereabout.
Another we read of in the Reign of Caligula, about 40. years after Christ, which was so dreadful, that it made that Emperour, then being in Sicily, to fly for it.
About the Martyrdome of the Romish S. Agatha it burned againe very fiercely; though some say, that by vertue of her intercession it was stay'd from reaching Catania.
Againe it burnt A. C. 812. in the Reign of Charles M.
Then from the year 1160 to 1669, whole Sicily was shaken with many terrible Earth-quakes, and the Eruptions of the same Mountain destroyed a vast tract of inhabited land round about it, and reacht as far as Catania; the Cathedral of which it destroy'd, and the religious men living in it.
Againe, in the year 1284. there happened another terrible fire about the time of the death of Charles king of Sicily and Arragon.
- A. 1329 until 1333. there was another. A. 1408. another.
- A. 1444. another, which lasted till 1447.
- A. 1536. another, which lasted a year.
- A. 1633. another, continuing several years,
A. 1650. it burnt on the North-East-side, and vomited so much fire, that by the fiery Torrents, caused thereby, great devastation was made, as Kircher relates in his Mundus Subterraneus; whose assistance we have also made use of in the foregoing Chronology together with that of Philotheus.
The same Author, having been in Sicily himself, observeth, that the people of Catania, digging for Pumice-stones, do find at the depth of 100 palmes (which is about 68. feet) streets pave with Marble, and many footsteps of Antiquity; an argument, that Towns have stood there in former ages, which have been overwhelmed by the Matter cast out of this Mountain. They have also found several Bridges of Pumice-stones, doubtless made by the flux of the fiery Torrents, the Earth being very much raised since.
Now whether these Eruptions are caused by actual subteraneous Fires, lighting upon combustible matter; or by Fire struck out of falling and breaking stones, whole sparks meet with Nitro-sulphureous or other inflamable substances heap'd together in the bowels of the Earth, and by the expansive violence of the Fire forc'd to take more room, and so bursting out with the impetuosity we fee; may not be unworthy of a Philosopher's speculation.
An Account
* It may be, that that, which is by M. Vassal, Publisher of this Relation, esteem'd a second Womb, is nothing else, but the true Matrix lengthen'd, or that, which by Anatomists is call'd Tuba Falopii. See. Bartol. Anatom. Refrom. l. i. c 27. and others. This Figure (which in the Cut here annex'd is the II.) represents the two* Matrixes found januar. 6 1669. by Benoit Vassal Chirurgeon, opening the Body of a woman of 32. years of age, of a sanguin Constitution, and a masculin port. These two Matrixcs were so well disposed by an extraordinary contrivance of Nature, that the True one had conceived eleven severall times, viz. 7. males and 4. femals, all born at the full time, and all perfectly well form'd; but they were at last follow'd by a brother yet a fætus, that was conceiv'd in an adjunct Uterus, in a place so little capable of distension, that seeking enlargement, after it had caused to the Mother for two months and an half grievous symptoms, did at last, being of the age of about 3. or 4. months, break prison and found its grave in that of its mother, by a very great effusion of blood in the whole capacity of her abdomen; which cast the mother into such violent convulsive motions for 3. days together, that she dyed of them. VVhereupon the said Uassal, after, having embalmed the parts, he had made at his house for a whole month together the particular dissection thereof, before all the most Curious and knowing Physitians, Chirurgeons, Apothecaries, Mid-wifes, and other Searchers of Nature, that are in Paris, thought good to preserve the History thereof by committing it and Figure of the parts spoken of, to the Press, together with a Table, for better better explanation; which we think fit here to annex in Latin:
A Pars vagina.
B. Orisicum internum Matricis apertæ
C. Collum Matricis.
D. Cavitas Matricis.
E. Linea separans cavitatem Matricis.
F. Uteri fundus.
G. Duo finus, inventiin fundo Uteri.
H. H. Crasities Uteri.
I. I. Ligamentum latum, five productio Peritondi lateris sinistri, continens in plicatura sua Vasa deferentia et ejaculantia.
K. Arteria Spermatica.
L. Vena Spermatica.
M. Testiculus.
N. Verum vas Ejaculatorium iserum fundo Vteri per sinum ibi inventum.
O. Alterum vas Ejaculans, quodingreditur Collum Uteri, Quò ejaculantur mulieres à conceptu.
P Tuba Vteri.
R. Ligamentum rotundum.
S. Ligamentum latum ab ea parte, ubi Spurisu hic Vterus formatus est.
u. Vena Spermatica.
T. Arteria Spermatica.
Y. Testiculus.
Z. Pars Tubœ.
2. Verum vas jaculatorium, quod fundum Uteri ingreditur per sinum supra dictum.
3 Alterum Iaculatorium, abiens in Vteri collum.
4. Pars lacerata à fœtu acuto.
5. Fætus eo situ, quo inventus fuit Amnio suo obvulutus.
6. Vasa Umbilicalia.
7. Placenta, substantiæ cuidam carnosæ adhærens.
8. Substantia carnosa.
9. Ligamentum rotundum. 
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An Accompt
of some Books.
WHen the Publisher intended to give notice to the World of Mr. Hobbes's Book very lately come abroad, concerning the Quadrature of the Circle &c. he soon found another, containing both that and the Confutation of it together.
The Author of this Confutation observeth two grand mistakes in Mr. Hobbs's Tract; the first in the Demonstration of his first Proposition, where these words, Aut ergo in Triangulo A C G, tiangulum rectangulum, cujus vertex sit A, æquale Sectori A C L sumi nullum potest; aut P Q L, C Y P, sunt æqualia, are upon our Authors Examination not at all prov'd, nor true. It seems, M. Hobbs had only prov'd, That If P Q L, C Y P, be equal, Then such a Triangle may be; but not the Converse, If those be not equall, then such a Triangle cannot be. For, if PQL be not equall, but a little bigger than CYP; and consequently, the Right-angled Triangle AYQ so much bigger than the Sector ACL; it is manifest, that a Line drawn parallel to the Base QY, a little nearer to the Vertex A, may cut off a like Right-angled Triangle (a little less then AYQ) which may be equall to the Sector ACL.
Billie; this (which overthrows all, in the examiners Iudgement) the other great mistake of M. Hobbs is alledged to be in the Demonstration of the second Proposition; where (supposing by the first Proposition a square found equall to a Circle) he argues, That, because the Square takes in as much of what is left out by the Circle, as the Circle takes in of what is left out by the Square; therefore a Cube answering to that Square, compar'd with a Sphere answering to that Circle, will doe so too: (which would have been well argued, saith the Examiner, of a Cylinder on that Circle, of equal height with a Cube on that Square; but not so of a Sphere.) So that he seems hereto have mistaken a Cylinder for a Sphere.
Besides these two (which doe influence all that follows) Mr Hobbes also, in his 2d Figure, supposeth (untruly, saith Dr Wallis) without proof, That (on the common Center A) the Arches drawn by Y. O. h, will cutt the Line AG in the same points b, c, l, where the streight Lines eb, zc, kl, (parallel to CG) doe cut the said Line A G: (which do influence all those Propositions, which depend on these Suppositions.) Other particular mistakes observed by our Author are here omitted.
N. On this occasion the Reader is made acquainted, that all the works of Dr Wallis, which of late have been scarce, are now to be had at the Shop of Moses Pitt Bookseller at the White Heart in Little Brittaine.
This History written in the Portuguese Language, as tis now moulded, by Padre Balthezar Tellez, Provincial of the Iesuits of Portugall, out of -that of Padre Manoel d' Almeyda, was not seen, I think, here in England before now, an Exemplar of it having been lately transmitted and presented to the R. Society from Lisbon by Padre Hieronymo Lobo (one of the same order) by the care of Sir Robert Southwell Knight, his Majesties Envoy Extraordinary to that Court.
Passing by the accompt and relations, given in this Book, concerning the kingdoms and Provinces, comprehended under the Abyssin Empire, and its customs, Government, Militia, Citties, Revenues, Emperors, Religion, Discoveries and pretended Conversions there made by the Portuguese, together with the Contradictions and Disappointments, which those of Religious Orders have met with in that Empire; We shall only take notice here of the Heads it contains of a Philosophicall call nature: Concerning which there is to be found a good description of the true Head and Course of the River Nile together with a plaine Mapp thereof; as also of the Lake Dembea, through which the said River passeth, and of all the Cataracts of it; and then of the Climate, and Temperature, Mountains, Fertility, Herbs, Trees, Animals Wild and Tame, and the inclinations of the inhabitants; besides, of the Read Sea, and the reason of its Appellation: Touching which particulars we must not here enlarge, but remit the Reader to the Book it self; or (since Copies of it are difficult to be had) to the Relations lately English'd by Sir Peter Wych, and printed for Mr Iohn Martyn; wherein the a maine passages, which concerne the Natural productions and other Curious Observables of that vast Country, are described.
- III. An HISTORICAL ESSAY Endeavouring a Probability, That the LANGUAGE of CHINA is the Primitive Language; by Iohn Webb Esquire. Printed for Nath. Brook in London, 1669. in 8o.
This surprising Essay attempts to make it out from Authorities, Judged by the Writer thereof unquestionable, That the Chinese have been a people, ever since the Flood of Noah and before the Confusion of Tongues (at which they were not present in his opinion;) That their Language hath continually in all times, from their first beginning of being a Nation, been preserv'd in written Books; That the Characters, wherein those Books be written, are the self same, which from all Antiquity were extracted from their Original Hieroglyphicks; That in those Characters their Language hath ever since consisted, and, according to them, is at this present day spoken purely; and that by the same Characters their Language is generally understood through the whole Chinese world: From all which, considered together, the Author concludes, that the Mother or Natural-Language of China remaines in its Antient purity without any alteration.
How credible the Allegations here deliver'd, and how cogent the Discourses and Inferences, grounded thereon, are, we must leave to the Iudgement of the sagacious Reader; and shall only further take notice of the singular diligence of this Author in collecting occasionally and abbreviating many of the most remarkable Observations of China recorded by the best Writers of that Empire. E. g. That the Chinese have had the Use of Letters longer by farr, than any other people; that the remote parts of Asia were planted before the dispersion of Babel; that China was the first planted Contry after the Flood; that those Plantations were undertaken and setled before the remove to Shinaar (the plaine where Babel was a building;) that the Chinese have diffus'd themselves to Corea, Iapan, Iava, Ceylon, Siam, Cambori, and Madagascar, if not Mexico, itself; that the China-wall hath lasted near 2000 years, and yet is not injured by time; that the Tartars are become Chinese, not these Tartars, to the preservation of the Mother-tongue of China; that the Chinese have subsisted 4000 years without any commixture with other Nations; that Commerce and Conquest have had no influence to change the Laws, Customs, or Language of that people; that the Historical Computation of the Chinese begins from 2207, years before Christ, which falls out with the 40th year before the Confusion of Tongues; that no Nation in the world is comparable to them for certainty in Chronology, &c.
And as to their Ingenuities and Arts, he notes, That the Loadstone and Compass hath been in use among them above 1100 years, and Paper- and Ink-making, above 180. years, both before Christ; that they prepare Ink of the smoak of oyle; that they have been long acquainted with the Invention of Gunpowder, and Fireworks, as also with the Manufacture of making and dying of Silk, invented by one of their Empresses; than their Potters mystery and the manner of making Porcelain vessels excels all other practises of that kind; and that they themselves do so much esteem it, as that they will not be served in Plate; that the Earth for making Porcelaine is to be had in the sole Province of Nanking, but that there they cannot make any Vessels of it, (whether it be from the quality of the water or wood, or temper of the fire, is not known;) but must transport it to Sinclesimo in the Province of Kiangsi; that that Earth is very leane, fine, and shining like, Sand, which they temper in water to reduce into the fashion of little square lumps; that they prepare and fashion it almost after the same manner as the Italians do make their Faenza-dishes, or as the Hollanders, in making their White Potters-work; that they nuke use of Indigo or Woad in painting their work with blew; but that for all this knowledge there remaines still something, necessary to make these vessels alright, which they keep very secret, insomuch that he passeth amongst them for one of the greatest Criminals, that reveals this Art to any but his own Children.
Lastly, as to their Art of Printing, which was invented among them about 50. years after Christ, their manner is, That they Cut their Letters with an instrument of Iron, (as we doe Wood-prints) upon some fit wood; lightly gluing the Written Copy thereon, whereby their Books are free from Errata's. They are very dextrous at it, and will cut a whole sheet, as soon as a Composer with us can set one; and one man will print off 1500. in a day. They have also this conveniency, that their Forms may be laid by for as many impressions as they please, and in the meantime print off no more copies, than they find sale for, &c.
As Montagne learnt the Latin tongue by Vse alone, his Father having plac'd him in his Child-hood with such persons as spake nothing but that Language with him; so does the Author of this Book undertake to shew, that without much difficulty the like maybe done with others, confirming what he saith, first, by an Example of a Boy, who having been bred, as soon as he was wean'd, (which was at the 22th month of his Age) like Montagne, speaks Latin frankly and properly, being hardly four years old, and hath been seen by the King and all the Court at Paris: secondly by two other Children, both very young, that are entred into the same conduit, and in a very hopeful way of success. To which the Author subjoyns a Discourse of the great Vsefulness of this Method, the maine advantage of it being, that Children may employ in Learning Arts and Sciences, all that time, which they spend in acquiring the Latin Tongue.
Advertisements,
1. THe Reader is desired, to insert in Numb. 47, p. 951. sect. 10. after these words, Why it goes too fast, this Note (as it may happen, when by same accident the Cheeks retaine not their proper figures.) And now if it shall be said, that upon any foulness the Watch will goe faster by reason of the shorter Vibrations of the Pendulum, it is to be considered, That this is only true when the Watches have no Cheeks, but when they have them (as in those hitherto used) 'tis not so.
2. If it should be demanded, Why in the same Tract use hath not been made of Tycho's Æquation of Time, nor of that of Bullialdus, but one is given different from both? The Answer it, That the Table, there publisht, is the Difference of the Right Ascension of the Sun at Noon from the Mean motion, accounting from th 1st of February; which must be the true Æquation; unless the Velocity of the Earth's Motion about her own Axis be not constantly the same.
Errat.
Numb. 47. p. 945. in the 2d columne blot out diff. before 6. 5. 1. and put it before the 3d rank of members above it, viz. before 11. 49. 56.
LONDON,
Printed by T. N. for John Martyn Printer to the Royal Society, and are to be sold at the Bell a little without Temple-Bar, 1669.