reafons, one of which is, that it has always been the practice to convert the equation of the fun's centre and the difference between his longitude and right afcenfion into time of the Primum Mobile, inftead of mean folar time, which, fays he, may produce an error of 2 feconds.

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

• But, in order to fet this matter in a clearer light, it will be first neceffary to confider motion and time, relatively to each other; for, except this be done, it will be impoffible to underftand any thing precife from converting a certain number of minutes and feconds into mean folar time, or time of the Primum Mobile.

• There are three different kinds of time used by aftronomers, fidereal time, apparent folar 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 fidereal day, which is divided into 24 equal parts or hours, and the hours into minutes, &c. This time is fhewn by a clock regulated to agree with the tranfit of the ftars across the meridian. The interval between the tranfit of the fun across the meridian one day, and his tranfit the next day, is called an apparent folar day, which is divided into hours, minutes, &c. of apparent time. The folar 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 fun's motion, which is un-'. equal. Therefore, aftronomers have devifed an imaginary time, called mean folar time; which is what would be pointed out by the fun, if his motion in right afcenfion from day to day was uniform, or, in other words, it is what would be pointed out by a fictitious fun or planet fuppofed to move uniformly in the equator, with a motion equal to the mean motion of the fun in longitude, its diftance from the first point of Aries (meaning hereby the mean equinox) being always equal to the mean longitude of the fun and as apparent noon is the inftant of the trae fun's coming to the meridian, fo mean noon is the inftant at which this helitious planet would come to the meridián. The interval beTween its coming to the meridian on any two fucceffive days is mean folar day, which is divided into hours, minutes, &c.

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

The equation of time, at the inftant of apparent noon, or of the fun's paffing 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 paffing the meridian expreffed in mean folar time to find which, we have the diftance of the mean fun from the meridian, at the inftant of apparent noon, equal to the difference between the fun's apparent and mean right afcenfion (both reckoned either from the mean or apparent equinox) which may be called the equation of right afcenfion. The question, therefore, comes to this, How many minutes and feconds of mean folar 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 fun, in returning to the meridian, describe 360° about the pole in 24 hours of mean folar time? whence it is plain, that his departure from the meridian is at the rate of 15° to 1 hour, and 15′ to one minute of mean folar time. Therefore aftronomers 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 folar time, and the motion of the Primum Mobile being compleated in 23 H. 56 M. 4 S. of mean folar 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 Connoiffance des Mouvements Celeftes has been computed in this manner, and the table in the 79th page of the Connoiffance for 1761 has been made ufe of, entitled, "A table to convert into degrees the time of a clock regulated according to the mean motion of the fun." The degrees of this table are evidently degrees of the Primum Mobile, I hour of mean folar time giving 15° 2′ 27,8", which answers to the motion of the ftars from the meridian, but not to the mean motion of the fun 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 fun from the meridian; an equal mistake to that of which he erroneously fupposes former mathematicians to have been guilty, in computing the equation of time. So that the equation of time in this ephemeris, befides the mistake arifing from the taking in the equation of the equinoctial points into the account, is conftantly too fmall in the proportion of 24 hours to 23 H. 56 M. 4 S. or of 366 to 365, or too small by I fecond upon every 6

minutes

minutes of the equation of time: and the mistake of 2 seconds, which was fuppofed 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 1 fecond of time, arifing from the mistake in taking the preceffion of the equinoxes into the account, produces 3 feconds, an error which, I apprehend, the aftronomical equation tables ufed fince Mr. Flamstead's time have but rarely exceeded.'

LVII. Aftronomical Obfervations made at the Island of St. Helena. By the fame.

LIX. Aftronomical Obfervations made at the Island of Barbadoes; at Willoughby Fort; and at the Obfervatory on ConftitutionHill, both adjoining to Bridge-Town. By the fame.

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

There are, likewife, in this publication, three articles relating to literary antiquities, viz. No.s 16, 22, and 60. The first of these contains obfervations on two Etrufcan coins, never before illuftrated.'-By the Rev. John Swinton, B. D. &c. The fecond confifts of remarks on the first part of Abbé Barthelemy's Memoir on the Phoenician Letters, relative to a Phoenician infcription in the Ifle of Malta. By the fame. And the third, from the fame hand, contains alfo remarks on the said Abbe's Reflections on certain Phoenician Monuments, and the Alphabet refulting from them.-But it is time to conclude this article.

MONTHLY CATALOGUE, For MARCH, 1766. MISCELLANEOUS.

Art. 7. An Efay on Luxury. Written originally in French, by Mr. Pinto*. 12mo. I s. 6d. Becket.

T

HE Author of this fuperficial performance, though apparently a man of fenfe and obfervation, treats his fubject in fo vague and defultory a manner, with fo little accuracy and precision, that (if we may judge from our own experience) the difcerning reader will have very little pleasure in the perufal of his effay.

He fets out with the following definition of Luxury:-Luxury, fays he, is the ufe 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 confiderable charter Holland.

tence agreeable is very different in different perfons, luxury, according to this definition, may be applied to very different and even oppofite characters. The man, for inftance, who employs his riches in relieving the indigent, in affifting the induftrious 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 expenfive in his table, equipage, drefs, or furniture. Such characters, it must be acknowledged, are but rare; this is nothing, however, to our Author's definition, which, at first fight, appears to be extremely inac-.

curate.

Luxury, indeed, may be confidered either as innocent or vicious, and though it is difficult, perhaps impoffible, 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 fubject, that he should avoid confufion and ambiguity as much as poffible, both for the benefit of his readers and his own reputation.

Luxury, fays Mr. Pinto, is exceffive in all thofe occafions, when individuals facrifice to their oftentation, to their convenience, to their fancy, their duty, and the interefts of the public; nor are individuals' led into this excess but by fome defects in the conftitution of their country, or by fome faults in the adminiftration. In this cafe, it does not fignify whether the nations are rich or poor, civilized or barbarous : when the love of country, and the useful paffions are not kept up among them, their manners will be depraved, and luxury will affume the cha racter of the current manners.'

This affertion must appear ftrange to those who are acquainted with human nature, or the hiftory of mankind, as it must be evident to all fuch, 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 facrificed their duty and the interefts of their country, to oftentation and private convenience. A well-modelled government and upright adminiftration, it is readily allowed, are abfolutely neceffary to form and fupport public fpirit and public virtue; but human nature must be new-modelled, before the felfish paffions lose their influence, or are made conducive to the public good.

The defire of acquiring and enjoying riches, our Author fays, are paffions natural to men in a state of fociety; all great focieties are maintained, enriched, and animated by them: luxury, therefore, he concludes, is a good; contributes to the greatness of ftates, 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 exceffes to which it may rife, are owing, he apprehends, to faults or defects in the adminiftration, or the conflitution, and will be reformed, when fuch defects are reformed.

To conclude; as far as we are able to collect Mr. Pinto's meaning from the confufed manner in which he writes, the principal defign of his effay is to fhew, that luxury has no natural tendency to beget venality and corruption, and that it has often been affigned as the cause of difor ders, which, in reality, have proceeded from an ill-modelled government. But this is no new difcovery. The Reader will meet with the fame fen

timents

timen's in many moral writers, particularly in Mr. Hume's ingenious Effay on Refinement in the Arts.

Art. 8. A new Introduction to English Grammar, in the fimpleft and rafieft Method poffible. By John Houghton, Master of a private Grammar-fchool at Namptwich in Chefhire. 8vo. Is. Cooke.

In the analyfis of human language, as in the anatomy of the human body, there are many dependencies, relations and connections, which have efcaped the most accurate refearches, and which, therefore, furnish objects for further enquiries. But the Author of this piece is, by no means, qualified for any fuch task; and, indeed, he pretends to nothing more than the laying down fimple precepts; yet he does not appear to have that accuracy which is neceffary even for this. Thus he fays 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, .g. cattle, ftubble, &c. Folks, he obferves, has no fingular number, and fo far he is right; but it is not, as he feems to fuppofe, upon the principle of the being added to it, for it has the fame power without it; and folks, which he holds to be the right, is the wrong fpelling; the word ought to be written folk. There are many other inftances 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 fenfible letter is annexed to the 4th Edit. of Dr. Lowth's letter to the Bishop of Glocefter.The Author politely rallies Dr. Brown, for his groundless apprehenfions with regard to the suppfid attack of his moral character, in certain paffages of Dr. L.'s celebrated letter to the author of the Divine Legation fee Review for Nov. 1765.

Art. 10. A free Address to the Author of the Effays on the Characteriflics. In Anfwer to his Letter to the Rev. Dr. Lowth. 8vo. 6d. Richardfon and Urquhart.

The Author of this addrefs obferves, very juftly, that Dr. Brown's letter contains nothing but one fingle point of knowledge, which the world has long been master of, viz. the Doctor's importance to himself.

Art. 11. An expoftulatory Letter to the Author of Effays on the Characteristics; occafioned by his Letter to the Rev. Dr. Lowth. 8vo. 6d. Ridley.

The defign of this fhort letter, which is written with fome degree of feverity, is to fhew, 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 lefs celebrated Mrs. Woffington, both of amorous

memory