careful and experienced, sometimes differ several minutes from each ether, while in general, their observations are found to agree. pp.24.25. The new and practical examples amount to 163; and in their formation, Mr. Myers has employed much care in enunciating them as they would actually occur at sea; in adapting the language to the occasion; and in embracing all the circumstances by which the truth of the result would be affected. These expedients are of considerable importance. By the first, the young navigator sees the theoretical part of his profession daily exemplified by the practical; the second renders the problems more easy to be understood; the third not only contributes to the accuracy of the results, in which the safety of both ship and crew is concerned, but it insensibly leads the mind to a habit of observation and thinking, which must ever be of great moment in those entrusted with command. We shall confirm these remarks by an example or two, which may be taken from any part, except a few of the first, which did not admit the exercise of the qualities we have specified. The following is Ex. 103. Suppose, that on the 21st of October, 1815, on board a vessel in North latitude 20° 34', and East longitude 115° 42', by account, the altitude of the sun's lower limb to be 17° 35', at 8h 10' A.M. by a watch that had been ascertained to be 38′ 15′′ before true time, on the preceding evening, in East longitude 115' 17. At 12h 30 by the same watch, suppose the observed altitude of the sun's lower limb was again taken and found to be 58° 48': the height of the eye in both these observations being 18 feet above the level of the sea, and the ship sailing at the rate of 6 knots an hour, on a North-East course; the height of the mercury in the barometer at the time of the last observation being 29.3 inches, and the thermometer at 76-46. Required the corrected latitude of the place of the last observation. Ans. 20' 42′ 18′′ N. The following example is one of those which Mr. Myers has worked as specimens, and affords a good idea of the accuracy of the precepts, and of his manner of clucidating them. On the 22nd of March, 1814, at 3 P.M. from observations of the sun's altitude, the chronometer on board a vessel was found to be 37′ 15′′ 4 too fast, in longitude 57° 24' west; and to have a daily rate of increase equal to 21. On the 2nd of May following, at ten minutes past five in the afternoon, the same chronometer was found to be too slow with respect to mean time at the place of observation, by 1h 18′ 22·5; and the daily rate of increase was then 3. Required the correction to be applied to the longitude of this last place of observation, as found from the first daily variation of the chronometer, and also the corrections of the longitude found by the same means on the 30th of March, and the 12th and 21st of April. Daily variation of the chronometer at the 1st obser. Mean variation Chronometer too fast at the first observation 2'1 3.6 Sum 5.7 Sum + 2.85 37 15" "4 Accumulated gain from March 22nd to May 2nd+1 26 ·3 41 days 2 10 at 21 per day Chronometer too slow at the 2nd observation ་ Diff. of longitude in time, between the two places of Since, by the nature of the question, the vessel was evidently sailing eastward, the correction of the + 1h 18 22-5 difference of long. on the 2nd of May, calculated diff: 7 42" with the first daily variation, 2'1, is The place arrived at is therefore east of that which is found by means of the first diurnal variation. Correction of longitude 7' 42', or 462" Multiple, from Table XI, answering log. 2-6646420 to 41 days 2 10, between March 865, comp. log. 7·0629839 22nd, and May 2nd Constant logarithm Sum-1-7276259 From the 22nd to 30th March, 8 days, Multiple from Table XI. 36 log. 1.5563025 Correction for the longitude found March 30th Also for the 21st of April the correction is found in the same manner, and is = 4′ 8′′4 These examples are followed by an easy method of clearing the distance, illustrated by examples, and accompanied by the tables requisite for its application. These last are succeeded by an introduction to the tables which conclude the work, showing the method of calculating those that were inserted in the French work, as well as those added by the author, as specified in the preface. Two of these last differ considerably from those in common use: and that difference is an improvements In the table of Logarithms of Numbers, the author has inserted the complements of the logarithms in the same line with the logarithms themselves; which renders the working of a proposition more easy and expeditious than by the common method; for, by taking the complement instead of the logarithm of the first term, the whole operation is reduced to that of adding three numbers together, and omitting 10 in the index. The complements of the sines and cosines in the next table are also attended with the same advantage. The differences inserted for every 10 seconds of a degree, likewise obviate the necessity of making a proportion for the proportional part of a minute; and reduce the whole operation to that of multiplying by a figure less than 10, and adding or subtracting the result. On a careful examination of this work, we feel fully justified in warmly recommending it to public notice. There is much perspicuity and some novelty in the conception, and not a little judgment every where apparent in the execution of it. And we ar persuaded, that naval officers of all descriptions will have sufficient reason to think themselves much indebted to Mr. My rs for so easy and useful an introduction to the astronomical prc.ples so essential to the knowledge of their profession. ART. X. Remains of the late John Tweddell, Fellow of Trinity College, Cambridge; being a Selection of his Letters, written from various Parts of the Continent; together with a republication of his Prolusiones Juveniles. To which is added an Appendix, containing some Account of the Author's Journals, MSS., Collections, Drawings, &c., and of their Extraordinary Disappearance. Prefixed, is a brief Biographi cal Memoir, by the Editor, The Rev. ROBERT Tweddell, A. M. Illustrated with Portraits, Picturesque Views, and Maps. London: Mawman, 1815. 4to. Price 31. 3s. pp. 660. JOHN TWEDDELL, the amiable and accomplished youth, whom this volume commemorates, was born on the 1st of June, 1769, at Threepwood, near Hexham, in Northumberland. He was the eldest son of Francis Tweddell, Esq. an able and intelligent magistrate; and his earliest years were much indebted to the care of a pious and affectionate mother. At the age of nine, he was sent to school at Hartforth, near Richmond, in the North Riding in Yorkshire, under the Rev. Dr. Raine, who discovered and encouraged the talents of his pupil. Before his commencing residence at the University of Cambridge, he was under the immediate tuition of Dr. S. Parr, and his ensuing academical career was distinguished by great success in his studies. His Prolusiones Juveniles were published in 1793; and were ardently commended by a number of eminent characters, who knew the value of the praise they bestowed. In the year 1792, he was elected Fellow of Trinity College; and soon afterwards, entered himself as Student of the Middle Temple. He manifested a strong partiality for the pursuits connected with diplomacy, in which it was part of his ambition to be employed. Partly with this view, although perhaps much more from the desire of extending his sphere of knowledge, he formed the design of travelling; and, on the 24th September, 1795, embarked for Hamburg, and proceeded through Germany, Switzerland, the North of Europe, and various parts of the East, till he arrived in Greece. He continued here some time "exploring with restless ardor, and faithfully delineating, the remains of art and science." A premature death closed all his mortal prospects on the 25th of July, 1799. He was buried in the Theseum; but, owing to various obstacles, his grave was not honored either with stone or inscription, until some years after; when, by "the exertions of Lord Byron, and another most enterprising traveller, Mr. John Fiott, of St. John's College, Cambridge, a stone was laid, and inscribed with an epitaph, composed by Mr. Walpole, in 1805." ΤΥΕΔΔΕΛΛ ΕΥΔΕΙΣ ΕΝ ΦΘΙΜΕΝΟΙΣΙ ΜΑΤΗΝ ΣΟΦΙΑΣ ΠΟΥ ΕΔΡΕΨΑΣ ΗΜΙΝ Δ ΟΙ ΣΕ ΦΙΛΟΙ ΦΙΛΟΝ ΩΣ ΚΑΤΑ ΔΑΚΡΥ ΧΕΟΝΤΕΣ ΗΔΥ Γ ΟΜΩΣ ΚΑΙ ΤΕΡΠΝΟΝ ΕΧΕΙΝ ΤΟΥΤ ΕΣΤΙΝ ΑΘΗΝΑΙΣ The personal character of Mr. Tweddell is illustrated in the subsequent passages. Of the principles and feelings which influenced his private conduct he thus speaks in a letter written about this period to his mother in the fullest spirit of confidence; "your fears on my account I know to be the result of great affection for me, but I think you will one day find that there was not very great occasion for them. I may do many inconsiderate things; indeed I feel that I often do I know it well-and I may chance to be betrayed into errors, of which it is very possible I may at some future time repent. For true it is what you observe, that my passions are very strong; and that I feel on most subjects that can interest me, most zealously and warmly. You have often desired me to check and tame them; and sometimes to a certain degree I do. But it is not in the power of Man, however plausibly the philosopher may maintain it in his closet, for any one essentially to alter his constitution. The moral complexions of Man are as different as the personal ones; and though a person may be enabled to improve the bent, he cannot change the tone, of his constitution. I feel myself a zeal and earn stness in almost every thing; and these properties, though they may be at times productive of inconvenience, have also their beneficial tendencies; for they will never allow me to engage in any thing which I do not feel to be right; and that will at all times be sufficient for my own conscience. Depend upon it, my life shall never be stained with one dishonorable act. I am as guilty of frailties and indiscretions as any one; but thus far I know myself thoroughly, that I abhor every thing that is bad and degrading, as well in private sentiment as in public conduct; I believe you know me also well enough to be convinced that this is true. I can say from the bottom of my breast, that I never do persist, and never will, in any thing deliberately, which I do not approve; and that at the same time what I do approve, I will always endeavour to act up to. In this therefore I agree perfectly with you, that rather than be guilty of any outrage against probity, I hope in God that I may be removed from the power of committing it. Time is the great prover of all things; and time may one day chance to show what I am, much better than my own professions." pp. 7, 8. Mr. TWEDDELL in his person was of the middle stature, of a handsome and well-proportioned figure. His eye was remarkably soft and intelligent. The profile or frontispiece to the volume gives a correct and lively representation of the original; though it is not in the power of any outline to shadow out the fine expression of his animated and interesting countenance. His address was polished, affable, and prepossessing in a high degree; and there was in his whole appearance an air of dignified benevolence, which pourtrayed at once the suavity of his nature and the independence of his mind. In conversation he had a talent so peculiarly his own, as to form a very distinguishing feature of his character. A chastised and ingenious wit which could seize on an incident in the happiest manner a lively fancy which could clothe the choicest ideas in the best language these, supported by large acquaintance with men and books, together with the farther advantages of a melodious voice and a playfulness of manner singularly sweet and engaging, rendered him the delight of every company his power |