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reasons, one of which is, that it has always been the practice to convert the equation of the sun's centre and the difference between his longitude and right afcenfion into time of the Primer Mobile, instead of mean tolar tine, which, says he, may produce an error of 2 seconds.

• Now I must here freely own, that as I could not, without some reluctance, and only from the fullest proof, allow all the mathematicians and astronomers, before this time, to have been mistaken in the manner of converting the quantities above-mentioned into time, so I can find no reason to conclude fo from what has been cited above: on the contrary, from a full confideration of the subject, I apprehend the method hitherto used by the mathematicians to be juft, and that the author has himself fallen into an equal mistake with that of which he accuses them.

• But, in order to set this matter in a clearer light, it will be first necessary to consider motion and time, relatively to each other ; for, except this be done, it will be impossible to underftand any thing precise from converting a certain number of minutes and seconds into mean solar time, or time of the Primum Mobile.

• There are three different kinds of time used by aftronomers, fidereal time, apparent solar time, and mean folar time. The interval between the tranfit of the first of Aries across the meridian one day, and its return to it the next day, is called a sidereal day, which is divided into 24 equal parts or hours, and the hours into minutes, &c. This time is shewn by a clock regulated to agree with the transit of the stars across the meridian. The interval between the transit of the fun across the meridian one day, and his transit the next day, is called an apparent solar day, which is divided into hours, minutes, &c. of apparent time. The solar day, it is manifeft, and its hours, minutes, &c. are of different lengths, at different times of the year: on account of which inequality, a good clock, which keeps equal time, cannot long agree with the sun's motion, which is unequal. Therefore, astronomers have devised an imaginary time, called mean folar time; which is what would be pointed out by the fun, if his motion in right ascension from day to day was uniform, or, in other words, it is what would be pointed out by a fialitious fun or planet supposed to move uniformly in the equator, with a motion equal to the mean motion of the sun in lon- . gitude, its distance from the first point of Aries (meaning hereby the mean equinox) being always equal to the mean longitude of the lun; and as apparent noon is the instant of the true sun's cotiing to the meridian, so mean noon is the instant at which this minioun planet would come to the meridián. The interval bewwwn on coming to the meridian on any two successive days is * Menn folar dny, which is divided into hours, minutes, &c.

of

of mean folar time ; all which it is manifest will preserve the same length at all times of the year.

(The equation of time, at the instant of apparent noon, or of the sun's palling the meridian, being equal to the difference between mean time and 12 hours, is also equal to the interval between the mean and true fun's passing the meridian expressed in mean solar time: to find which, we have the distance of the mean fun from the meridian, at the instant of apparent noon, equal to the difference between the sun's apparent and mean right ascension (both reckoned either from the mean or apparent equinox) which may be called the equation of right ascension. The question, therefore, comes to this, How many minutes and seconds of mean solar time doth the mean fun take to move this distance up to or from the meridian? Aftronomers hitherto have allowed i minute of time to every 15 minutes of right afcenfion, and fo in proportion; and, I apprehend, juftly too; for does not the mean sun, in returning to the meridian, describe 360° about the pole in 24 hours of mean solar time? whence it is plain, that his departure from the meridian is at the rate of 150 to 1 hour, and is to one minute of mean solar time. Therefore astronomers have not converted the equation of right afcenfion into time according to the motion of the Primum Mobile ; for, the equation of time being mean solar time, and the motion of the Primum Mobile being compleated in 23 H. 56 M. 4 S. of mean solar time, therefore 15° motion of the Primum Mobile does not answer to 1 hour of mean folar time (though it does to 1 hour of fidereal time) but to the 24th part of 23. H. 56 M. 4 S. or 59 M. 50; S. And it appears, that the equation of time in the Connoissance des Mouvements Celeftes has been computed in this manner, and the table in the 79th page of the Connoissance' for 1761 has been made use of, entitled, “ A table to convert into degrees the time of a clock regulated according to the mean motion of the sun.”. The degrees of this table are evidently degrees of the Primum Mobile, 1 hour of mean solar time giving. 15° 2' 27,8", which answers to the motion of the stars from the meridian, but not to the mean motion of the sun from thence, which is 15° to - 1 hour of mean folar time: whence it appears, that this writer hath evidently fell into the mistake of taking motion or space of the Primum Mobile, instead of the mean motion of the sun from the meridian ; an equal mistake to that of which he erroneously supposes former mathematicians to have been guilty, in computing the equation of time. So that the equation of time in this ephemeris, besides the mistake arising from the taking in the equation of the equinoctial points into the account, is conftantly too small in the proportion of 24 hours to 23 H. 56 M. 4 S. or of 366 to 365, or too small by i second upon every

6 minutes

minutes of the equation of time and the mistake of 2, seconds, which was supposed to be found in the old manner of reducing the equation of right afcenfion into time, really takes place in this new method; which, added to i second of time, arising from the mistake in taking the preceffion of the equinoxes into the account, produces 3 ; seconds, an error which, I apprehend, the astronomical equation tables used since Mr. Flamstead's time have but rarely excceded.' LVII. Afironomical Observations made at the Island of St. Helena.

By the same. LIX. Astronomical Observations made at the Island of Barbadoes ;

at Willoughby Fort; and at the Observatory on ConftitutionHill, toth adjoining to Bridge-Town. By the same.

Both these are very useful papers, containing a great number of very accurate astronomical observations; but are, from their very nature, incapable of abridgement.

There are, likewise, in this publication, three articles relating to literary antiquities, viz. Nos 16, 22, and 60. The first of these contains . observations on two Etruscan coins, never before illustrated.'-By the Rev. John Swinton, B. D. &c. The second consists of remarks on the first part of Abbé Barthelemy's Memoir on the Phænician Letters, relative to a Phænician in. scription in the Isle of Malta. By the same. And the third, , from the same hand, contains also remarks on the said Abbe's Reflections on certain Phoenician Monuments, and the Alphabet resulting from them.-But it is time to conclude this article.

MONTHLY CATALOGUE,

For MARCH, `1766.

MISCELLANEOU S. Art. 7. An Essay on Luxury. Written originally in French,

by Mr. Pinto*. 12mo. I s. 6 d. Becket. T

HE Author of this superficial performance, though apparently a

man of sense and observation, treats his subject in so vague and delulcory a manner, with so little accuracy and precision, that (if we may judge from our own experience) the discerning reader will have very little pleasure in the perufal of his eflay.

He fets out with the following definition of Luxury :-Luxury, says he, is the use which we make of riches and of industry, in order to procure an agreeable exittence.- -Now, as the idea of what renders ex

A merchant of considerable character - Holland.

Atence agreeable is very different in different persons, luxury, according to this definition, may be applied to very different and even opposite characters. The man, for infiance, who employs his riches in relieving the indigent, in affifting the industrious poor, in encouraging genius, and promoting schemes of public utility, may be denominated luxurious, though he is extremely temperate and frugal, and far from being expensive in his table, equipage, dress, or furniture. Such characters, it must be acknowledged, are but rare ; this is nothing, however, to our Author's definition, which, at first sight, appears to be extremely inac-, curate.

Luxury, indeed, may be considered either as innocent or vicious, and though it is difficult, perhaps impossible, to determine exactly where it ceases to be innocent and begins to be vicious, yet it is reasonably expected of every author who writes upon the subject, that he should avoid confusion and ambiguity as much as possible, both for the benefit of his readers and his own reputation.

• Luxury, says Mr. Pinto, is excellive in all those occasions, when individuals sacrifice to their ostentation, to their convenience, to their fancy, their duty, and the interests of the public; nor are individuals led into this excess but by fome defects in the constitution of their country, or by some faults in the administration. In this case, it does not fignify whether the nations are rich or poor, civilized or barbarous : when the love of country, and the useful passions are not kept up among them, their manners will be depraved, and luxury will assume the character of the current manners.'

This affertion must appear strange to those who are acquainted with human nature, or the history of mankind, as it must be evident to all such, that under the best administrations, under the most perfect forms of government that human wisdom hath as yet been able to plan, there have been always found individuals who have sacrificed their duty and the interests of their country, to ostentation and private convenience. A well-modelled government and upright administration, it is readily allowed, are absolutely necessary to form and support public spirit and public virtue ; but human nature must be new-modelled, before the selfish pallions lose their influence, or are made conducive to the public good.

The desire of acquiring and enjoying riches, our Author says, are passions natural to men in a ftate of society; all

great

societies are maintained, enriched, and animated by them : luxury, therefore, he concludes, is a good ; contributes to the greatness of states, and the happiness of mankind; and the great point, he tells us, should be to encourage, enlighten, and direct it.

The abuses that may be made of luxury, and the excesses to which it may rise, are owing, he apprehends, to faults or defects in the administration, or the conftitution, and will be reformed, when such defects are reformed,

To conclude; as far as we are able to collect Mr. Pinto's meaning from the confused manner in which he writes, the principal delign of his essay is to shew, that luxury has no natural tendency to beget venality' and corruption, and that it has often been assigned as the cause of disoro ders, which, in reality, have proceeded from an ill-modelled government. But this is no new discovery. The Reader will meet with the fame sentiments in many moral writers, particularly in Mr. Hume's ingenious Eflay on Refinement in the Arts. Art. 8. A new Introduction to English Grammar, in the simplest

timents

and afieft Method possible. By John Houghton, Master of a private Grammar-school at Namptwich in Cheshire. 8vo. is. Cooke.

In the analysis of human language, as in the anatomy of the human body, there are many dependencies, relations and connections, which have escaped the most accurate researches, and which, therefore, fornish objects for further enquiries. But the Author of this piece is, by no means, qualified for any such talk; and, indeed, he pretends to nothing more than the laying down simple precepts ; yet he does not appear to have that accuracy which is necessary even for this. Thus he says of the word people, that it has no plural ; but he might more properly and more justly have said that it has no fingular, the termination le being in our language many times of a plural power and quality, 1.g. cattle, stubble, &c. Folks, he observes, has no fingular number, and so far he is right; but it is not, as he seems to suppose, upon the principle of the s being added to it, for it has the same power without it; and folks, which he holds to be the right, is the wrong spelling; the word ought to be written folk. There are many other instances of Inaccuracy in this little tract, which we do not care to be at the trouble of enumerating. Art. 9. A Letter to the Rev. Dr. Brown. From Dr. Lowth.

8vo. An Half-sheet. This genteel and sensible letter is annexed to the 4th Edit. of Dr. Lowth's letter to the Bishop of Glocester. The Author politely rallies Ds. Brown, for his groundless apprehensions with regard to the supplied attack of his moral character, in certain passages of Dr. Li's celebrated letter to the author of the Divine Legation : lee Review for Nov, 1765. Art. 10. A free Address to the Author of the Essays on the Charac

teristics. In Answer to his Letter to the Rev. Dr. Lowth. 8vo. 6d. Richardson and Urquhart.

The Author of this address observes, very justly, that Dr. Brown's letter contains nothing but one single point of knowledge, which the world has long been master of, viz. the Doctor's importance to himself. Art. 1 1. An expoftulatory Letter to the Author of Essays on the Charac

teristics ; occafioned by his Letter to the Rev. Dr. Lowth. 8vo. 60. Ridley. The design of this short letter, which is written with some degree of severity, is to hew, that no attack has been made by Dr. Lowth upon Dr. Brown's moral character. Art. 12. A Dialogue in the Shades, between the celebrated Mrs. Cibber, and the no less celebrated Mrs. Woffington, both of amorous

merrory;

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