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1814.1

of the Mosaic Account of the Creation.

10. Having thus determined an epocha in the past events on the earth, characterized by a certain state in which it must have been; continuing to follow the dictates of facts, and the progress of our natural knowledge, I ascend to a time, defined in §§ 30 and 31, when nothing of what we now observe on our globe, namely, the mineral strata, composing the whole known mass of our continents, the sea and our atmosphere, could have been produced, because liquidity, without which no chemical effect could take place, (and consequently, no precipitation of the substances of our strata, nor any formation of elastic fluids) did not yet exist. The epocha, therefore, when all those effects began, is particularly characterised by the production of liqui'dity on our globe. But what new cause was required, for that new effect?

11. Pursuing this analysis, I explain, § 34, in what liquidity consists: it is produced, without exception, at every temperature, by the union of the elements of the liquified substance, with a certain quantity of fire; or of the fluid, which, when uncombined, produces heat, (an effect measured by our thermometers,) but loses this faculty when combined, with other substances, in which state it is called latent. Therefore, in § 35, I thus more distinctly determined the epocha to which we are to ascend, as the beginning of all the operations of which we see the effects on our globe: "when a sufficient quantity of fire was united with the substance which, when liquified, constitutes water, and in that state che mically combines with a great number of elements which they help each other to dissolve."

12. We now arrive at the point that directly relates to Mr. Pilgrim's attack; which point is introduced in the above letter, by the following question: "How was fire produced?" This question I then follow from the knowledge acquired in experimental philosophy; and in studying my deductions from it, Mr. Pilgrim would find a subject of reflection, which it does not appear he has ever considered. Fire is a compound fluid, and into its composition enters light, a substance which possesses chemical affinities, and indeed is the essential ingredient contributing to all chemical processes. Without light, in combination with another ingredient, no fire exists; and without fire, there exists no liquidity. Continuing this analysis, I arrive at the final conclusion expressed in § 42, of

207

the same letter: "Nothing of all that we see on our globe could begin to be operated, previous to the introduction of a certain quantity of light into the whole mass of elements, till then incapable of chemical action on each other. There fore the beginning of all the geological phenomena that we know, takes its date from this union."

13. This last conclusion referring to the whole of what I had before proved, it is evident that the moment of the first production of liquidity on our globe, must have been that of the commencement of all the operations impressed on it, which have been the object of geological researches; which operations continued without interruption, till the birth of our present continents. Had Mr. Pilgrim been acquainted with all which here I have only sketched, would he not have judged, that the only way of attacking me fairly, had been to meet me on that ground, and contradict either the facts or the conclusions?

14. His next objection is expressed in the following words. "Provided we ad. mit Mr. De Luc's opinion, it must evidently appear, that this planet, called earth, must have existed many ages prior to the creation of the sun; a supposition that will not be entertained by any person of common understanding: and more over, we are to conclude, that all the fixed stars are but in a juvenile state, compared with the age of the globe we inhabit; an idea that must be equally exploded by every person who has the least acquaintance with astronomy." This must appear plausible to those who, like Mr. Pilgrim, are not acquainted with my works, and in particular with the Letters to Prof. Blumenbach, above quoted; but had he read only these letters, he could not have expressed himself in that manner. I shall repeat here briefly what he would have found there.

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15. This sublime preamble, In the beginning God created the heaven and the earth, evidently comprises the stars, the sun, and other celestial bodies, as well as the earth. They had received their projectile motions, and they influenced on each other by gravity, which in particular occasioned the revolution of the planets round the sun; and their liquidity to a certain depth, with their mo tion on their axis, had given them the form which they actually possess. But were the sun and stars then luminous ? If Mr. Pilgrim had known, or attentively read my works, to which I have referred,

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he might have found first, that I am more 'acquainted with the physical part of astronomy than he appears himself to be; then he would have seen the results of experiments and observations which prove, that in order to enable bodies in themselves capable of phosphorescence, actually to emit light, there is required some previous interior chemical process, to decompose their moleculæ, and disengage the light which has entered them as an ingredient.. A few examples, which I purpose giving in your next, will be sufficient to evince this proposition. Windsor. J. A. DE Luc.

To the Editor of the Monthly Magazine.

SIR,

THE

HE following paragraph is literally copied from a provincial paper of this month. It deserves to be known beyond the limits of the circulation of the paper; and if you think it and the few remarks annexed, will not disgrace a corner of your valuable repository, they are at your service.

at

"A singular circumstance took place about a week ago in the neighbourhood of Penrith. A farmer, who had always expressed a great aversion to baptizing or christening, had a child which died; and in consequence of his predilection that none of his children should ever undergo the ceremony, the parishioners refused it burial, and application was made where a grave was prepared; but, previous to the time of interment, the circumstance came to the knowledge of the worthy vicar, who ordered the grave to be filled up again. When the child was brought to the town, they were much disappointed at what had taken place; and after waiting a length of time to no purpose, were necessitated to return home, and seek out for some other place of burial."

The worthy, worthy, worthy vicar! A poor innocent child is refused the rites and right of sepulture, notwithstanding a grave had been prepared for it, must rot on the surface of the earth, be wor ried by dogs, or devoured by the crows! Is this christianity? is this the established religion of a civilized people? From what I have read of the humanity of the Hot. tentots, I think such a circumstance could never have taken place amongst them. Tell it not in Westmorland, nor publish it in the streets of Kendal, lest the Philistines, the infidels, the heathen, the Turk, hear it and rejoice.

Lancaster, Dec. 1813.

D. B. P. ECCLESTON.

To the Editor of the Monthly Magazine.

D'

SIR,

R. O. GREGORY has accused me with making "the resistance, or, as Dr. Hutton terms it, 'efficacious force of the pier,' to depend in a great measure upon the weight of the arch itself," but did not this occur from negligence, and "looking about" him? for surely, had he looked before him he must have "discerned" the difference between the two expressions so closely following each other; the first dénoting Dr. Hutton's force of the pier, which does not depend in any measure upon the weight of the arch; and the second deneting what I have termed "the sum of the resistance of the pier," and doth "depend in a great measure upon the weight of the arch itself;" for LGXA is the measure of what that dependance is (A being here put for "area of semiarch"), and is the proper resistance to what Dr. Hurton terms "the efficacious force of the arch to overset the pier, or turn it about the point G," when his efficacious force of the pier, as there expressed, is the proper resistance to the effective force of the arch.

This distinction Dr. Hutton was not, and Dr Gregory does not now seem to be, aware of; otherwise he would not inculcate the doctrine he does in his concluding paragraph, for there he tells me, I must be convinced "that the matter, which by its pressure upon a pier tends to overset it, does not by means of the turned." same pressure prevent it from being overshews me that matter by its pressure upAll this I grant, provided he on a pier doth tend to overset it, but not otherwise; for what I contend for is, that matter by its pressure upon a pier does tend to prevent its being overturned; although the same matter by its pressure against the pier, will tend to overset it.

By what can be collected from the mode of argument made use of in this attack, does it not appear to "a discerning public," as better calculated to intimidate me from writing upon the subject than to confute what I have already written? and is it not probable he fancies that by degrading my abilities he can dissuade the young bridge-builder from relying upon them, and by this means increase the demand for Dr. Hutton's remodelled work, which he informs us is at length published? But if those are his ideas, he is mistaken, as I have already received letters of thanks, for what has been published of mine in this Magazine; having in the number for May, 1812, not

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only

1814.]

Mr. Parry in reply to Dr. O. Gregory.

only shewn that the Emersonian theory
of arches, as Dr. Hutton has explained
it, in his "Principles of Bridges," is not
a theory adapted to practical purposes:
but one is there given that can be so
adapted, and that without any fluxionary
process, but by common arithmetic only.、
See also another letter of mine in the
same publication for October, 1812,
where I have added a second step to
Mr. Ware's construction, in order to
perfect what he fancied he had com-
pleted before; which was to equilibrate
an arch by geometrical construction, and
had a third step been added to it, the
height of the Emersonian vertical would
be obtained.

This construction is not new, it being no other than an application of the Pythagorean Problem, or 47th of Euclid; so well known to carpenters and masons, partieularly the former, as it is by its means he finds the length of his rafter, after half the breadth of the building and the height of the roof are given; but for our purpose it is sufficient to observe, that by a proper application of it, every thing necessary, both for the equilibration of arches, and also their comparative and relative strength, may be found, and a knowledge of the latter is of more utility to the practical builder than the former; as an arch, when strictly in equilibrio, according to the terms of the theory, will not admit of the smallest extraneous weight being placed upon any part of it, without destroying that equi librium, but when attached to matter, acquires, what is termed, strength. And it is on this the stability of arches depends; hence it is obvious, a knowledge of the quantum of that strength is a desi deratum in the science, not hitherto noticed by any of the mathematicians who have treated on this subject; at least not to my knowledge.'

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209

not sufficiently explained in my last, I trust it will in this; for here I shall have the assistance of Dr. Gregory himself, the work before alluded to being no other than his "Treatise of Mechanics." For article 208, vol. 1, of this work, not only contains enough to prove the truth of what I before gave as my opinion, but also sufficient matter for correction and improvement, of which it stands in much need.

What I shall first notice in this article, is an equation intended to express the force of an arch, and the resistance of a pier, when supposed to turn on a centrė of rotation; the principles that this equation is deduced from, being those of mechanics; but the place and angle of abutment, to which it is applied, have no claim or affinity to that science; and that this is a fact will appear evident, even from the directions given to find this place and angle,

The rule is as follows: "Draw from the middle of the key voussoir, a tangent to the intrados, and produce it till it again meet the middle of another voussoir." This point, or middle of this last voussoir, is to be considered as the place of abutment, and a line from the centre of curvature through that point, shews the angle this abutment forms with the vertical; the curve from its vertex to this point is all that is to be taken as the semi-arch, and the remaining part is to be considered as part of the pier, and to act with it in resisting the force of the arch. Hence it appears, that the place of abutment is to be governed by the length of the voussoirs, without any reference to the direction of the pressures; for it evident, that their length determines the extent of this tangent line.

To shew what will result from adopting this rule, an example or two will be sufficient; therefore suppose a line drawn It may be objected, that nothing upon from N to V, on the figure in my last letthis subject is noticed in my second letter, this line will intersect the curve at ter, and this I admit; neither is there here any other than hints, but such hints as cannot injure, yet may stimulate to farther enquiry; and is all I can afford in this place, whatever I may do hereafter. But even grant that nothing more is done than what I have already written, and is published in the Monthly Ma gazine; it is not very probable the young artist will refer to Dr. Hutton's fluxion ary process for instruction in the theory of arches, when it may with more ease be obtained, by referring to a few letters in this publication, or even to his carpenter. Then in respect to piers, if that subject is

33° 15′ distance from the vertex, which, if taken as the semi-arch, the length of the voussoirs to admit this line, being drawit on their face, must be upwards of four feet, which is more than necessary (when stability only is required) in an arch of 51.25 feet radius; for the length of those in the celebrated arch over the Täff, in Glamorganshire, where the radius is 87 5, is only 33 inches, and in respect to stability there can be no doubt, for that arch has been erected upwards of 60 years, and is now perfect.

Then as the length of those voussoirs is sufficient, and the comparative

strength

strength of arches is as the squares of the voussoir at the vertex, or depth of the arch at that point, when compared with radius of curvature to that point, the length of the voussoir for that purpose, only in the first arch, need be no more than 254 inches. For as 87.5: 51.25 :: 332:25 252. But then the extent of this line, and consequently the place of abutment, will be at 23 degrees from the

vertex.

But if a line after this manner was produced on the face of the voussoirs in the

last arch, it would extend only to 20° 10, and then there would be 33 degrees to be attached to the abutment, and to act as part of it, for the whole semi-arch is 53 10'; and farther, if a vertical line was let fall from this place of abutment, it would be distant from the vertical axis only 30 feet, and from the face of the real abutment 40 feet, the semi-span be ing 70 feet. Such are the results that would ensue from adopting this rule, but it requires no farther comments, as it puts an end to our controversy.

I shall now return to this equation, and

here it is to be observed that the vertical

pressure Nm, and the horizontal pressure ma, which by me were considered separate, are here considered as combined in one; in the direction of Na. Then

137.762 (N m2) + 16·422 (m a2) = 41.1756 the other pressure, or they are rather lines, in the direction and propor tionate to the pressures. The vertical pressure is always equal to the weight or area of the semi-arch, which is here 809, and then the horizontal pressure =351·795, but that in Nax A Nm

will be

maX A Nm the direction of the line Na

855.7, the initial pressure.

This last pressure, acting in the direction of the line Na continued, acts against another line or lever not represented on the figure, but supposed to be produced from G, the fulcrum or centre of rotation, on which the pier is supposed to turn to the line Na, and at right angles to it, which short line or lever shall be denoted by G h, and whose length, upon investigation, is found to be 1.7863, which multiplied by 8557, the initial pressure, is 1528 52, the effective force of the arch to overset the pier; then the weight of the pier, represented by its area, acting at E, as one end of the bended lever E Gh, being multiplied by the distance from E to G, will determine and shew the resistance of that pier; hence one whose thickness is 6-912, is

sufficient in this case. For 6·912 (GL) X64, (EF) ×3·456, (EG) = 1528.82, the resistance of the pier to the effective force of the arch, and nearly the same as that force. This is the result when the vertical and horizontal pressures are considered as combined in one, or Dr. Gregory's method; next for that when they are considered separate, or the method which I have adopted.

Nin,

Now ma is substituted for MA, Dr. Hutton's force of the arch will be expressmaXA ed by × La=7120·33, and to produce a resistance equal to this force will require a pier 14-917 feer in thickness, for 14.917 X64X7·485=7120.63, nearly the same; but this is in consequence of no notice being taken of the vertical pressure of the arch, which counteracts the horizontal as before. Therefore I added it to the resistance of the pier, taking the thickness to be as in the first case, and then it was

max A

Nm

× La or

7120 33 GLXEFXEG+LGXA, or 1528-825591.808 7120.628, Dr. tion might have been differently and Hutton's force of the pier; but this equa

more elegantly expressed by

max A

X

N m La-LGXA, or 7120.33-5591 8081528 522, the resistance of the pier nearly as before.

Here we have the results from three different methods of investigation, one of which is conformable to Dr. Gregory's theory, all agreeing with each other, but differing with Dr. Hutton's; which in op position to me the former now supports. JAMES PARRY, Bridge-builder. Cardiff, Feb. 1, 1814.

For the Monthly Magazine. On the ORIGIN of the TITLE of KING of France, assumed by the KINGS of

ENGLAND.

A MANUSCRIPT history of the an

cient disputes between the sovereigns of England and France has lately been brought forward in Paris. It was written in 1572 by John Renard, a person unknown to bibliographers.

In this work we are told that Edward the Third of England, to induce the Flemings to assist him in his war against Philip of Valois, engaged to put into their hands, Lille, Douay, and Bethune, taken from them by France. To this offer the Flemings answered, that by taty they were restricted from making war against the king of France, under the penalty of forfeiting two millions of florins

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1814.]

King Charles's Ring-dial.-Legal Murder.

rins, besides falling under the heavy censures of the church.

Anxious however to accede to Edward's proposal, the Flemings, after mature deliberation, hit upon an expedient by which their honour and their advantage could be reconciled. They counselled Edward to claim the throne of France, to quarter the arms of that country with those of Eng. land, and openly to designate himself King of France. In that case, said the wily Flemings, we can conscientiously acknowledge you as sovereign of the towns in question; we can honestly accept them as a gift at your hands; and we can lawfully and securely carry arms against the usurper Philip of Valois.

The title of King of France was always afterwards employed by Edward, even when writing to Philip himself; and it is not a little curious, that the relinquish ment of that title, offensive and insulting to a great and independant nation, pertinaciously refused to the most powerful legitimate sovereigns of France, was at a late period, without difficulty, acceded by Britain to a person not unfrequently styled, in that very country, a lawless usurper. X.

To the Editor of the Monthly Magazine.

R,

IR Thomas Herbert relates in his

King Charles I. that the king, on the morning of his execution, commanded him to give "the Duke of York his large ring sun-dial of silver, a jewel his ma jesty much valued; it was invented and made by Mr. Delainaine, an able mathematician, who projected it, and in a little printed book shewed its excellent use in resolving many questions in arith metic, and other rare operations to be wrought by it in the mathematics." Permit me to ask your readers for any information they possess respecting the existence of this ring-dial, and particularly if Mr. Delamaine's "little printed book" is in existence, its size, number of pages, date, and by whom published.

March 1, 1814.

M. E.

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211

Criminal Trials in Scotland, from 1536 to 1784, with historic and critical remarks, by Hugo Arnot, esq. advocate: Edinburgh, 1785." At page 324 is the following case.

Thomas Aikenhead appears to have been about twenty years of age; his father, who had been a surgeon at Edinburgh, was dead. Sir James Stewart, his majesty's advocate, by special order of the privy council, served him with a criminal indictment before the court of Justiciary for blasphemy.-Records of Justiciary, Dec. 23, 1696.

The libel sets forth, that blasphemy against God, or any of the persons of the blessed Trinity, or against the holy scriptures, or our holy religion, is a crime of the highest nature, and severely punishable by the laws of God, by those of this and every well governed realin, and par ticularly by act of parliament, 1696. Sec. v. c. 2, 11 William.

That, notwithstanding, the prisoner had repeatedly maintained in conversation, that theology was a rhapsody of ill-invented nonsense, patched up partly of the moral doctrines of philosophy, and partly of poetical fictions and extravagant chimeras. That he ridiculed the holy scriptures, calling the Old Testament Ezra's fables, in profane allusion

That

railed on

Christ, saying he had learned magic in Egypt, which enabled him to perform those pranks which were called miracles. That he called the New Testament the history of the impostor Christ. That he said Moses was the better artist, and the better politician: and he preferred even Mahomet to Christ. That the holy scriptures were stuffed with such madness, nonsense, and contradictions, that he admired the stupidity of the world in being so long deluded by them. That he rejected the mystery of the Triity as unworthy of refutation, and scoffed at the incarnation of Christ, saying that a theanthropos, or God-man, was as great a contradiction as a hircocervus, or goat stag, or that a square was a round. That he laughed at the doctrine of redemption: and said the notion of a spirit was a contradiction. That he cursed Christ, and argued against the being of God; maintaining that God, the world, and nature, are all one thing, and that the world existed from all eterni

ty. That he said the inventors of the scripture-doctrines would all be damned if there was such a thing as rewards or

Christianity itself would soon be extir

pated.

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