ART. V. The Nautical Almanac, and Aftronomical Ephemeris, for the Year 1772. Publifhed by Order of the Commiffioners of Longitude. 3s. 6d. fewed. Nourfe. 1770. Hether we regard our country in a political or commer WH cial view, the art of Navigation is of the highest importance and use. To this we owe our fuperiority and credit abroad, as well as our fecurity and profperity at home. We are furrounded with an element, by the command of which we can defy the machinations of foreign powers, and enrich ourfelves with the produce of diftant nations. Our fituation, in. this refpect, is a bulwark, on which we can more confidently rely, than on the beft concerted 'meafures of the most upright. and difcerning minifters; and we may have reafon to congratulate ourselves on account of the fecurity we derive from it, against the. attempts of an adverfary, whom our timidity may render vain, and our abject fubmiffion encroaching and imperious. It requires no prophetic fpirit to prognofticate a period, in which we may be obliged to recur to our maritime ftrength to combat the pernicious effects of our ministerial weakness.-But as we are not fond of indulging gloomy furmifes, we will hope that fuch a period is far diftant. We are difpofed to wish, that the temporary fufpenfion of the dreadful calamities of war and bloodshed, which every lover of his fpecies and of his country would gladly avoid, will iffue in an established and durable tranquillity; that we shall long enjoy the bleffings of freedom and peace, without moleftation, and with grateful united hearts; and that our commercial interefts will yet flourish, free from impediment and restraint. Our commerce is already extended through the four quarters of the globe; our richly freighted fhips traverse the feas, which wash the fhores of remoteft kingdoms, and with their expanded fails invite the gales of various climates. Our navigators are justly celebrated through the world; and we may boaft farther advancements both in the theory and practice of failing, than any other nation under the fun. An art of fuch extenfive benefit, and in which we already fo much excel, deferves all the patronage and encouragement which genius and flation can afford it. Having attained fo near perfection, we fhould ftrive to be altogether per fect.-There is one problem, on the solution of which the defirable perfection very much depends: this relates to the determination of the longitude at fea.-Many ingenious and laudable attempts have been made towards refolving this important problem. Time-pieces have been conftructed, and tables have been formed, for this purpose. The latter method feems to bid faireft for fuccefs. The late Profeffor Mayer of Gottingen had brought his tables of the moon, now publifhed by authority of the Commiffioners of Longitude, to a fufficient degree of exact nefs nefs to determine the longitude within a degree, as appeared by the trials of feveral perfons who made ufe of them: but the neceffary calculations were too difficult and tedious for general ufe. To remove this inconvenience, is the primary defign of the work before us; though, at the fame time, it must greatly contribute to the improvement of Aftronomy, Geography, and Navigation in general. The world is much indebted to the favour of the legislature, and to the commendable labours of the aftronomer-royal, for the extent and accuracy of these tables. The work contains, to use the Editor's own words, every thing effential to general ufe, that is to be found in any Ephemeris hitherto published, with many other useful and interefting particulars never yet offered to the public in any work of this kind. The mariner may eafily find the longitude by the help of thefe tables; the problem is now reduced to the computation of the time, an operation equal to that of an Azimuth, and the correction of the distance on account of refraction and parallax, which is alfo ren dered very eafy by feveral methods here propofed. The Editor, at the defire of the Commiffioners of Longitude, has drawn up the explanation and use of the feveral articles contained in the Ephemeris, and inftructions, together with examples, for finding the longitude at fea, by the help of the fame. He has likewife, with great ingenuity and pains, calculated several tables to render the use of these more eafy and expeditious, for which he is juftly entitled to the acknowledgments of the public. The preface to this work contains the refult of feveral obfervations, made at the Lizard, by the direction of the Board of Longitude, for more accurately determining the difference of longitude between this place and the obfervatory at Greenwich, which is found to be 5° 15' weft;-together with corrections of errors of lefs moment, relating to the longitude of the Cape of Good Hope. The Ephemeris itfelf contains twelve pages for each month. The first page is divided into four columns: the three first of which contain the days of the month, of the week, and the Sundays and feftivals through the year. The laft column fhews, at top, the moon's phases; and beneath are contained mifcellaneous phænomena, fuch as eclipfes of the fun and moon-occultations of planets, or fixed ftars, not less than the fourth magnitude by the moon, as they are to happen at Greenwich. by the tables the conjunctions of the moon with all stars not lefs than the fourth magnitude-the conjunctions, oppofitions and quadratures of the planets with the fun-the entrance of the fun into the feveral figns, together with any other remarkable phænomena. P 4 Occulta Occultations of the fun, and occultations of the fixed ftars by the moon, obferved in places whofe latitude and longitude are known, are of ufe in correcting the lunar tables; and if the latitude of the place of obfervation only be known, the longitude may be determined from them. Eclipfes of the moon, however, are more readily applied to this purpofe: the longitude, in this cafe, being the difference of time of the obfervation and that fet down in the Ephemeris converted into degrees, for which tables are provided. The other phænomena are of importance in the fame respect. The two firft columns of the second page of the month contain the days of the month and week as before; next follow the fun's longitude, right afcenfion in time, declination, and the equation of time, with the difference from day to day. Page 3d contains, in five columns, the femidiameter of the fun, the time of his paffing the meridian, his hourly motion, the logarithm of his diftance, and place of the moon's node, for every fixth day and at the bottom of this page are the eclipfes of Jupiter's fatellites, whenever they are vifible. In the fourth page of the month, we have the longitudes and latitudes of the planets, both heliocentric and geocentric, their declination and apparent time of paffing the meridian, calculated for every fixth day. The fifth and fixth following pages (and not the 7th and fifth, as by a mistake of the Editor, the references are made), contain the moon's place, and all the circumftances relative to her motion, and her diftances from the fun and proper flars, from which her distance fhould be obferved for finding the longitude at fea. The longitudes, latitudes, and declinations of the moon, and time of her paffing the meridian, afford the like ufes with the fame circumstances of the planetary motions, and many more befides. For the fake of greater precifion, the moon's longitude, latitude, right afcenfion, declination, femidiameter, horizontal parallax, with its logistic or proportional logarithms, are computed twice a day to noon and midnight, and may be readily inferred for any intermediate time with the greateft exactness. The distances of the moon from the fun and fixed ftars, are fet down to every three hours of apparent time by the meridian of Greenwich, and are defigned to relieve the mariner from the neceffity of a calculation, which he might think prolix and troublefome, and to enable him, by comparing the fame diftances obferved carefully at fea, to infer his longitude readily, and with little danger of mistake, to a degree of exactnefs, that may be thought fufficient for moft nautical purposes. The Editor obferves, that though the distance of the moon from the fun or ftars, well obferved with a good inftrument, is fufficient to de terming termine the longitude, with the help of the Ephemeris, always within a degree, and generally much nearer, yet it will conduce to ftill greater accuracy, if the observer takes the distance of the moon from two ftars, or the fun and a star, or, when the moon is between 90° and 120° distance from the fun, from the fun and two stars, if he can be fo lucky as to obtain these several obfervations. The longitude being computed from the obfervations made with each star refpectively, the mean of the results is to be taken as probably approaching neareft to the true longitude. The laft page of the month (and not the fifth) fhews the configurations of Jupiter's fatellites, or the apparent positions of the fatellites with refpect to each other and to Jupiter at fuch an hour of the evening or night, as they are moft likely to be obferved, and ferve to diftinguish the fatellites from one another. For the diftinct ufe and application of each column of the above tables we must refer to the work itself; and shall conclude with obferving, that to this Ephemeris are annexed, the eclipfes of the third fatellite of Jupiter in the years 1771 and 1772, computed from the new tables published with the Nautical Almanac for last year and two tables are likewife added, for more readily finding what eclipfes of Jupiter's fatellites will happen, when Jupiter is at leaft 8° above, and the fun as much below the horizon; viz. one containing Jupiter's hour-angles to different declinations, when his altitude is exactly 8°, and the other the fun's hour-angle or time from noon, when he is depreffed 8° below the horizon. This number, moreover, contains Mr. Lyons's folution of a problem in Mercator's Navigation, propofed formerly by Dr. Halley, as wanting to complete that doctrine, and defigned to determine the courfe fteered, when a ship has failed from a given latitude a certain number of miles, and has altered her longitude by a given quantity; which folution, fays the Editor, cannot but be acceptable to the curious. At the close of this article, it may not be improper to fubjoin a brief account of the tables requifite to be used with the aftronomical and nautical Almanac, which, though a feparate publication, are intended to accompany the other, and thereby to render the operations more eafy and more accurate. They chiefly relate to the correction of the errors of the moon's distance from the fun or stars, arifing from refraction and parallax; and they. contain several tables and rules for this purpose: befide tables for converting degrees and minutes of the equator into time and the contrary tables of the longitudes and latitudes of nineteen of the brightest ftars and nearest the ecliptic, fuch as are moft proper to take the moon's diftance from, for finding the longitude at fea, together with a table for finding the aberration of a zodiacal ftar in longitude-two tables, one for chu fing proper ftars, from which to obferve the moon's diftance, and another of limits and aquila;-tables of corrections of the moon's longitude and latitude;-of the right afcenfions and declinations of the principal fixed ftars, with their variation for ten years;of multipliers ;-of the depreffion or dip of the horizon, and a table of proportional logarithms; the nature and use of all which are explained, in their proper places, by the ingenious Editor. This volume contains, likewife, inftructions for finding the longitude at fea by the help of the Ephemeris, comprized in feveral articles; together with particular cafes exemplifying the rules laid down. ART. VI. Cafes in Surgery, with Remarks. Part the Firft. By Charles White, F. R. S. one of the Corporation of Surgeons in London, and Surgeon to the Manchester Infirmary. To which is added, An Effay on the Ligature of Arteries, by J. Aikin, Surgeon. 4s. 6d. bound. Johnston. 1770. THIS is a valuable collection of chirurgical cafes and re marks, feveral of which have already been made public; fome of them in the Philofophical Transactions, and others in the Medical Obfervations and Inquiries: but the ingenious Author imagined it would be full as agreeable to the readers to fee them all together in one volume, efpecially as fome of them are connected with thefe now firft published, and they help to confirm each other. I have likewise, fays he, selected fuch cafes from a number which my father took minutes of when he was in full practice, as are fimilar to those of my own, which I have now transcribed for publication.' He proceeds: • The few cafes I have here given of the ftopping of bleeding arteries by fponge, are not intended to fhew its utility in all hæmorrhages whatfoever, but in those where the ligature could not poffibly be made ufe of, or in fuch as had refifted the moft approved methods of practice, and of confequence brought the life or limb of the patient into danger. I propose to give the public a fecond part of this work, as foon as my avocations in business will permit me, and am sufficiently furnished with materials for that purpose.' Without making an abftract of the feveral articles which compofe this volume, we fhall briefly obferve, that it contains fome new and useful obfervations concerning diflocations and their reduction; and likewife concerning the re-union of fractured bones, the extremities of which have remained long difunited. Among other curious cafes, we have the fingular one in which the upper head of the Os Humeri was fawn off, and yet the en |