« السابقةمتابعة »
that Thould be vered, by a very the proportiona
he two diament be found to be in Lapland and Perth:
a supposition by no means to be admitted : it will therefore follow that the dimensions given by our Author cannot be depended upon, and consequently the corrections he has given are not the corrections that should be made use of, if any at all are necessary. Sir Jsaac Newton discovered, by a very subtile theory, founded on the observations on pendulums, that the proportion between the two diameters of the earth is as 229 to 230; and this perhaps will at last be found to be nearer the truth than that resulting from the mensurations made in Lapland and Peru; which must certainly be preferred to that resulting from the menfurätions made in Lapland and France, as the distance between them is much greater, and the accuracy of the Peruvian menfurations appear, from the accounts published of them, to be at least equal to either of the former.
In a word, it appears from the whole, that though these menfurations are abundantly sufficient to prove that the earth is an oblate spheroid, yet they are by no means accurate enough to determine the precise dimenfions of that spheroid. And we will venture to add, that accurate obfervations made in different latitudes on the oscillations of penduluins, afford a more certain method for determining the dimensions of this spheroid, than actual mensurations. Upon observations of this kind Sir Isaac's theory is founded; and as the result of the mensurations in Lapland and Peru approximates much nearer to Sir Isaac's than that resulting from the mensurations in Lapland and France, it is a strong argument in favour of the former; and also that Sir Isaac's dimensions should be used preferably to either. But if these dimensions are used, our Author's corrections will be much too gieat.
Nor is this all. It must be remembered that the latitudes and longitudes of all places have been settled by the common methods of observing : it will therefore be neceffary that these be all corrected from Mr. Dunn's principles before any method of this kind can be used to advantage ; because otherwise it will tend to mislead the mariner instead of assisting him to reach his, intended port with greater safety. But this will be taking a great deal of pains to very little purpose; for if these errors (if indeed such they are) accurately balance each other, they can be of no prejudice. It should also be remembered that the art of navigation cannot be rendered too plain and easy. To encumber it with a multiplicity of tedious rules, would be to disappoint the very intention of that neceffary art'; because the greater number of navigators cannot be supposed to have made any progress in the sublimer parts of mathematical learning.
We have hinted in several parts of this article, that we doubted whether any corrections of this kind were necessary; and that we' may not seem to have done this without sufficient
reason, it will not be improper' to add the opinion of the celebrated Maupertuis on this subject, a gentleman whole abilities are fufficiently known, and who made it his study to confiter all the advantages that would result from knowing the true figure of the earth." :“ That the plumb-line, says this able mathematician, is every where perpendicular to the surface of the waters; and, coniequently, to the plane of the horizon, which is the plane that touches the surface of the waters in each place, cannot be doubted. But, is the surface of the waters the fame in all places with the furface of the earth? We see it is in general. "The coasts are every where so little elevated above the level of the sea, that we may consider the surface of the earth as a continuation of the surface of the sea. But may there not be some place where this furface is unequal ? Some place where the plumb-line, though it may be perpendicular to it, would not have, with respect to the axis, the fame inclination as it would have at some other place, equally distant from the equator? . All astronomical observations fhew the contrary : it is very true that ihe error which this would occasion in computing the altitude of the pole, would not be easy to discover. But all the declinations of the stars determined in such place would differ from the declinations determined elsewhere; nor would there be any agreement, with regard to these declinations, between the different observatories now erected in all parts of the earth. A thing which has been so far from being observed, that, on the contrary, the more astronomy is improved, the more exact is found the agreement between all the declinations of the stars determined in different places.” Rudimens de Geographie. Chap. XV.
Continuation of the Posthumous Works of Dean Swift. See our
last, p. 13. IN our last month's publication we gave a brief view of the 1 Political Essays, &c. of this celebrated Writer; and now we come, according to the order in which these papers have passed through the press, to,
1.A Letter from Sir John Brown to Dr. Swift,' relating to fome political scrape in which Sir John was involved, and to some correction he had received from Swift's pen. This letter, we think, might well have been spared from the present collection, as it certainly makes no part of the Dean's Writings, and as its insertion here can possibly answer no valuable end whatever; unless that of filling up four pages in quarto.
- 2. - A Letter on Mr. M°Culla's Project for a New Species of Copper Coin, for the Kingdom of Ireland.' This scheme the Dean examines with the same public-spirited view with which he animadverted on Wood's half-pence. Mr. M‘Culla's project does not appear to have been so much calculated for the disadvantage of the country as Wood's undoubtedly was; but fill the Dean thought, and he has here made it suficiently obyious, that the peo; le would have been greatly injured by this fecond expedient; however, as the kingdom was then greatly distrefled for want of fmall change, as the crown did not seem at all inclined to redress this grievance, and as M'Culla's scheme was capable of being so far improved as to answer the end required, he, accordingly, here proposes such a method of carrying this scheme into execution, as would at once supply the wants of the public, without incurring an unnecessary loss ; and at the same time, not leave the first projector entirely unrewarded for his contrivance. This is all that ever we heard of Mr. M‘Culla's scheme; and what became of it, is not here said. Probably all private projects of this kind, were at length superceded by the royal mint.
3. • 'On Doing Grad; a Sermon, on the Occasion of Wood's Project, 1724. In this plain and sensible discourse the Dean warmly recommends the amor patrid; and endeavours, principally, to prove these three points: 1.' That there are few people fo weak or mean, who have ic not sometimes in their power to be useful to the public. 2. That it is often in the power of the meanest among mankind, to do mischief to the public. 3.
That all wilful injuries done to the public, are great and aggrayated fins in the light of God.?-Among other instances of the want of public virtue which the Dean mentions as characteristic of the limes in which he lived, is the following: which, alas! is still more applicable to our own times.--I Have we not feen men, says he, for the sake of some petty employment, give up the very natural rights and liberties of their country, and of mankind, in the ruin of which themselves must at last be involved? Are not these corruprions gotten amongst the meanest of our people, who, for a piece of money, will give their votes at a venture, for the disposal of their own lives and fortunes, without considering whether it be to those who are most likely to betray or defend them!-- But if I were to produce only one instance of an bundred wherein we fail in this duty of loving our country, it would be an endless labour, and therefore I shall not attempt it.?
4. A Proposal that the Ladies and Women of Ireland should appear constantly in Irish Manufactures.' Discovers the Wrio ter's most laudable resentment and concern for the miser
Tuxury: an with becor for me
able state of Ireland, as the political and commercial affairs of that country were circumstanced, in 1729.
5.A Letter to the Archbishop of Dublin, concerning the Weavers.' The purport of this is collateral with that of the preceding article. The patriot Dean here, likewise, takes a melancholy view of the then state of Ireland, and with a spirited and manly commiseration, expatiates on the ruin of her trade, the vast yearly remission of the rents into England, for the support of absentees, the destructive importation of foreign luxury and vanity, the oppression of landlords, and the discouragement of agriculture. All these evils he considers as past the poffibility of a cure ; except that of unnecessary importations of foreign silks, laces, teas, china-ware, and other articles of luxury : and in order to enforce the remedy of this grievance, he labours with becoming zeal, to recommend the wear of Irish manufactures, both for men and women, and the use of the innocent and wholesome produce of their own soil.–Apologizing for the acrimony with which he usually treats these subjects, (though he is sometimes droll and ludicrous upon them too) he observes, that it is hard for a man of common spirit to turn his thoughts to such fpeculations, without discovering a resentment which people are too delicate to bear.-There were, indeed, people who could ill brook the rough and manly freedoms which our excellent Author was apt to take, on these occasions, because, more than their delicacy, their interests were likely to be affected by his just remonstrances and keen invectives : and, accordingly, in return, they gave him fufficient trouble, as far as lay in their power, by setting on foot prosecutions against his printers, and offering rewards for discovery of the Author, in order to punish him as a Libeller.-But, as his cause was good, his resolution steady, his perseverance unshaken, he finally triumphed over all his opponents; who deservedly funk into the infamy they fo justly merited : while the patriot Dean became the idol and the glory of that kingdom, for the welfare of which he so worthily exerted those talents with which the Almighty had most bounteously endowed him. In truth, the Dean was, in this part of his character, whatever may be thought of him as a divine, or even as a wit, A TRULY GREAT AND GOOD
6. Answers to Letters from unknown Perfons,' 1729 The first of these answers, relates to the same subject, in general, with the two last-mentioned papers; but more particularly to the great emigration of the Irish, at this time, to North-America ; occasioned by the want of employment, and by their various distresses at home. In this paper, he takes occasion to animadvert, with great severity, on the prevailing tuin toward extravagance, and every kind of difliparion, for which, it seems,
the the ladies of Ireland were at that time remarkable: those of the present generation, we hope, are by no means liable to the fame charge. Is it not, says he, the highest indignity to human nature, that men should be such poltroons, as to suffer the kingdom and themselves to be undone, by the vanity, the folly, the pride, and wanton ness of their wives ; who, under their present corruptions, seem to be a kind of animal fuffer'd, for our fins, to be sent into the world for the destruction of families, focieties, and kingdoins, and whose whole study seems directed to be as expensive as they poslibly can, in every useless article of living; who by long pra&tice can reconcile the most pernicious foreign drugs to their health and pleasure, provided they are but expensive; as starlings grow fat with henbane; who can play deep several hours after midnight, sleep beyond noon, revel upon Indian poisons, and spend the revenue of a moderate family, to adorn a nauseous, unwholsome, living carcafe?'- This cha. racter of the Irishi ladies, of Dean Swift's time, will naturally induce many of our readers to turn their eyes towards our fair country women, and to put the query — what would the Dean have said of the English ladies? The second of these leta ters relates to several particulars mentioned by the Dean, for the improvement of the country, and reformation of the common people; who, in all countries are sufficiently in need of reformation ; but what this sarcastic writer here says of the native Irish, i. e. the country people, or peasants, is monstrously revere, and, we believe, a gross exaggeration of the truth, altho' the truth might suffice to give us a very unfavourable idea of those poor, uncultivated Hibernians. One thing here mentioned, for their improvement, may, perhaps, to fome' readers, seem a little extraordinary ; but we cannot help looking upon it as an excellent hint : viz. the abolition of the Irish language, This our Author thinks might be effected, in that kingdom, in less than half an age, and at a very triling expence : at least so far as to oblige all the natives to speak only English on every occasion of business, in shops, markers, fairs, &c. • This, says he, would in a great measure civilize the most barbarous among them, reconcile them to our customs and manner of living, and reduce great numbers to the national religion, whatever kind may then happen to be cftablished. The method is plain and fimple ; and although I am too defponding to produce it, yet I could heartily with some public thoughts were employed to reduce this uncultivated people from that idle, savage, beastly, thievilh manner of life, in which they continue sunk to a de"gree, that it is almost impossible for a country gentleman to find a fervant of human capacity, or the least tincture of natural honesty :' thisa surely laying, is too much; but it might come "netrer the truth, ac the time when this paper was written,