things which tend not only to comfort, but to virtue, | 60,000 white people above 20 years of age, who and even to Freedom-lawless violence, under the cannot read or write,-to know that England has decrees of that vile usurper, Judge Lynch-and two millions. It is wiser to compare her with the perhaps above all, the foulness of our newspaper 4,500 of Massachusetts, or the 44,000 of New press,-are sins for which Mr. Dickens does not York, or the 33,000 of Pennsylvania: the first give us one lash amiss. Truth never outwent fic- having as many, the second thrice, and the third tion farther, than two village newspapers in Ten- twice as many white inhabitants as Virginia has. nessee outgo Boz's Eatanswill Gazette and Eatans- A word more of Mr. Dickens' Article. I am will Independent, in violence and scurrility. And glad of his severity (if it were less ill-natured) the daily observation of us all,-even daily re- towards the poetasters, whom I have long ranked marks now current among us,-show that our News- among the country's nuisances. Who can dissent paper Press generally is, and that we feel it to be, from the justice of his animadversions upon the worse than Dickens' worst representations of it. Epic yclept "Washington," the common-place It was with difficulty, three days ago, that I could tameness of Pierpont,-the "feeble verbosity" of get a gentleman of very high standing for intelli-"the American Hemans," and the utter inanity gence and honor, (no dyspeptic, either, nor other- of ninety-nine hundredths of those newspaper and wise morbidly inclined,) to except the National In- magazine rhymesters, clerks, foredoomed their telligencer, the New York Evening Post, the Bos-father's souls to cross, and penning stanzas when ton Courier, and one or two others, from the gene- they should engross? Rhymesters, to whom Obliral censure for unfairness, vulgarity and bitterness. vion has a fair, indefeasible claim; and of whom We have not taken the criticisms of foreigners Mr. Griswold vainly. endeavors to defraud her, in (including Boz) upon our manners and country, as his late collection of their indiscretions.*—But towe ought to have done. We have been too thin-wards Hail Columbia and the Star-Spangled Banskinned-too resentful. The uses of censure, like ner,―towards Drake's American Flag, and Trumthose of Adversity, are sweet, if rightly taken. bull's McFingal, Mr. Dickens has not been just, as "Though like a toad, ugly and venomous," it "wears any jury of sensible Englishmen could easily be yet a precious jewel in its head," to such as know satisfied by an examination of them. To six Amehow to find that jewel. If, instead of bristling up rican Poets, he has dealt out a measure of praise at those ill-natured criticisms, we had carefully ex- with which even themselves would probably be satisamined ourselves to see how far they were just, fied: Alfred B. Street, Mrs. Brooks of Louisville and to mend our ways accordingly, it would have ("Maria Del Occidente"), Ralph Waldo Emerson, been wiser. Pictures that others draw of us, are Halleck, Bryant, and Longfellow. "Halleck," in fact the very fulfilment of Burns' prayer which he says, "is the author of a noble lyric, Marco is in every body's mouth :Bozzaris.' Had he written nothing more, he must have earned a high popularity; but he has written much more, equally distinguished by a refined taste and cultivated judgment."—" We are too much pressed for space to afford room for the whole of By flying into a passion at such pictures, we be- this poem, and are unwilling to injure its effect by come unable to see what truth they contain; and an isolated passage. The chrysolite must not be lose all the benefit of having the poet's prayer broken."-I wish his praises even of the three granted. By-the-by, if our foreign monitors wish whom he most admires, had not been alloyed by us to profit by their schoolings, they ought to infuse some qualifications that savor of the ill-nature and more kindness into them. Advice, to man, woman illiberality that pervade nearly the whole" Article." or child, is sure to be rendered powerless by spite Mr. Dickens ends with a paragraph powerfully or arrogance in the giver !—Suppose Mr. Dickens Though I fear its effect in America will be in his Notes for General Circulation, and in his marred by its coming from him, and by its repullate Review, had substituted kindness, and that sive context, yet quote it I must, for the sake of its good-humored banter in which he excels, for the truth. How impressively it reinforces the (ensaarling tone in which he utters his well deserved tirely too long) essays of Mr. Simms, in your blame of our filthy spitting habit-of our fast eatJanuary and March numbers! ing-and our other peccadilloes?—why, he would have done more for our amendment than all our own lecturers and satirists combined; and at the same time have doubled his popularity in America, instead of annihilating it. "O would some Power the giftie gie us, And foolish notion." true. "We repeat," says Mr. Dickens in the Foreign Quarterly, "that it is matter of regret, and not of censure, that circumstances through which she has hitherto struggled, and to which she continues to be exposed, are fatal to its cultivation. With the literature of England pouring in upon I do not see what we gain, or that we at all her, relieved of the charges of copyright and taxation, it is refute the foreign calumniators, by shewing their impossible there can be any effectual encouragement for own countries to be worse than ours. It would *The Poets and Poetry of America. By Rufus W poorly mitigate the evil to Virginia, of having Griswold. America should be destitute of a national literature. The native talent. Literature is, consequently, the least tempt- Navigation and Geography, and ought to be exeing of all conceivable pursuits; and men must float with cuted with all the refinements of modern science. the stream, and live as they can with the society in which The method of finding the Longitude at sea, by they have been educated. Even were the moral materials be wished for." Good bye, Mr. Messenger. Louisa, March, 1844. Q. Q. Lucian Minor TO THE HON. T. W. GILMER, SECRETARY OF THE NAVY. by which this vast deposit of human dregs is supplied, Lunar Distances, first noticed by Werner and apother than they are-purer, wiser and more refined,-still plied by Frisius, and afterwards perfected by HalAmerica could not originate or support a literature of her ley, Lacaille, Maskalyne and others, has been usuown, so long as English productions can be imported free ally relied upon for the determination of a ship's of cost, and circulated through the Union at a cheaper rate than the best productions of the country. The remedy for place. Many attempts have been made to simplify this is obvious, and its necessity has long been felt on both and shorten the calculations which it exacts, but sides of the water,-a law for the protection of Interna- they are still somewhat tedious in practice. The tional Copyright. Such a law would be valuable to us, length of this method would form no serious obsimply in a commercial point of view-but to America its jection to its employment, if its results, when arri advantages would be of incalculably greater importance. ved at, were always sufficiently accurate. Their It would lay the foundation of a comprehensive intellectual movement which never can be accomplished without its inaccuracy arises, indeed, from no defect in the help; and by which alone, she can ever hope to consolidate theory of the process employed, but from the dif and dignify her institutions. We trust the day is not far ficulty experienced in making, with sufficient predistant when the unanimous demand of the enlightened of cision, upon the unstable deck of a ship, the obserboth countries will achieve a consummation so devoutly to vations upon which its application is founded, as well also as from the errors in the Lunar Tables. An error of 30 seconds, in the measurement of the apparent angular distance of the moon from a fixed star, will produce an error of of a degree in the longitude; and this error will not unfrequently be increased a fourth of its whole amount by the errors as yet existing in the best Lunar Tables. Under the equinoctial line, this error in a ship's place would be about 20 miles. To arrive at a tolerably correct result, the errors of observation must be eliminated as far as possible, by taking in immediate succession several distances between the moon and stars, both to the East and West of her; and by using the time as deduced from the altitude of the sun, taken in the afternoon of the preceding day. This last precaution is necessary because the horizon is not sufficiently well defined at night to measure with precision the altitude of But the time as deduced from an observaa star. tion made several hours before, will be affected by the change in the ship's place during this interval, and consequently cannot be determined with any Randolph Macon College, Feb. 29, 1844. very great degree of accuracy. When, however, MY DEAR SIR,—When I last enjoyed the plea- attention has been paid to every circumstance sure of a personal interview with you, I promised which can affect the accuracy of the final result, that I would commit to writing and transmit to you, and when the instruments employed are of the best a few suggestions in respect to the proper organi-construction, this method, it must be granted, is zation of the Marine Observatory now in erection competent to determine with sufficient approxima at the seat of Government. Your recent appoint- tion the longitude of a ship at sea. It is neverment to the Secretaryship of the Navy, upon which theless very desirable that a method, which is se you will allow me to congratulate both you and the laborious in practice, which is so uncertain in its country, reminds me of that engagement and of results, unless applied with the utmost care and the propriety of fulfilling it at this time. skill, and which is of no account at such times as The organization of the Observatory must be the heavens are overcast, should be replaced by determined in a great measure by the objects which one easier of application and at all times available. are intended to be accomplished by its establish- This end is likely to be attained by the use of the ment. It will, therefore, be proper to direct your Chronometer constructed with all the modern reattention to some of the most obvious and impor-finements in the art of Horology. This instrutant of these. ment is now made to maintain a steadiness of rate The following letter was drawn up by the advice of the Hon. Thomas W. Gilmer, late Secretary of the Navy. It was commenced on the day after the fatal accident which occurred on board the Steamer, "Princeton ;" and was not entirely finished, when the sad news of his death reached me. In him I have not only lost a valued friend whom I have known from my boyhood, but the country has been deprived of an able and faithful public servant. I at first laid aside my pen without any intention of resuming it; but have since been induced to finish the letter for publication in the Southern Literary Messenger, in which have appeared so many interesting papers on the subject of the Navy. The first which I shall notice is the rating of which is truly remarkable, when we consider the Naval Chronometers. various causes which have a tendency to affect its This is a service of great importance to both motion. The manner in which it accomplishes all the purposes of navigation, may be indicated in very few words. If a Chronometer could be constructed so perfectly as to indicate, with precision, the mean solar time under the meridian to which we refer the longitudes of places, suppose under that of Greenwich, the determination of the longitude of a ship at sea would be as easy and as accurate as we could desire. To render, however, even the best Chronometer subservient to the purpose of finding longitudes it must be rated with great care. There are several considerations, which should induce us to regard this process as not so simple and easy as to be performed with sufficient accuracy by the use of the sextant and artificial horizon, as was generally practised before the establishment of the Marine Observatory. In rating a Chronometer, three things are to be determined; first, its absolute error, at a given moment, upon the mean solar time of the assumed meridian; Secondly, its daily rate at that moment; Thirdly, the law by which that rate is altered from day to day. But it is not sufficient to determine these three particulars, without special reference to the circumstances under which the Chronometer has to perform. It would be only necessary to find the mean solar time at the ship, and to compare it with that at the primitive meridian as indicated by the Chronometer, and the difference of these times would be the longitude of the ship, East or West, according as its time preceded, or succeeded that of the primitive meridian. It is indeed impossible, in the present state of the arts, to give to the Chronometer this supposed degree of perfection; but it may be constructed to run so nearly uniform, that in the It was very satisfactorily ascertained in the interval of six, or seven weeks, longitudes deter- voyage made by Capt. Buchan to the Arctic remined thereby will be as accurate as those deter-gions in 1818, that the rates of Chronometers are mined by lunar distances, and for shorter intervals considerably different on board and on shore. of time even more so. In confirmation of this This conclusion has been subsequently confirmed last statement I refer you to the Chronometrical de- by a Series of Observations instituted by Mr. Bartermination of the longitude of New-York by Mr. low, with a view to determine the cause of this Dent of London. The longitude of New-York, difference and the laws by which its action is goas given by Mr. Walker, is 4h. 56m. 04.6s. West | verned. (See "Phil. Transactions" for 1820.) of Greenwich. This result was obtained, as well That the difference of rate really exists and is as I remember, from several solar eclipses. That quite too great to be neglected, will be made eviobtained by Mr. Dent from the indication of three dent by the following results of some experiments Chronometers transported on board the "British by Lieut. Wm. Mudge and published in the "EdQueen" is 4h. 56m. 3.35s., which differs by only inburgh Phi. Journal" for Oct., 1821. a second from the former one. That these differences are not attributable to the imperfection of the Chronometers themselves is plain from an examination of their rates either on land or sea. Let us take for example No. 1970. noon from day to day, and within sight of a vessel having all its metal on board and its Chronometer placed as it is intended to be kept when on a voyage. The Chronometer may be rated by a daily comparison between its mean noon and that indicated at the Observatory, allowing for the difference of longitude between the vessel and the Observatory, which will perhaps be very small, but yet ought not to be overlooked in researches of such delicacy. The vessel also, after the interval cí a case of No. 503 Arnold, by 5 or 6 seconds per the sea rate. In every case the position of the day. It is, then, a question of much importance plate must be determined experimentally, and will to Navigation, how may the sea rate of a Chro- be different for different ships. nometer be accurately determined? It is not pos- I regard it very important to test the correctness sible, in our present state of ignorance in respect of Mr. Barlow's views. This, it seems to me, may to the action of the metal of a ship upon the mo-be done in the following manner: Let a signal be tion of a Chronometer, to give to this question a displayed at the Observatory at the instant of mean satisfactory answer. We do not yet fully understand the mode in which this influence acts, much less the laws by which it is governed. Whether the metal of a ship becomes magnetized by the directive power of the earth, and influences the balance of the Chronometer as a magnet would do; or, whether a degree of magnetism is inherent in the balance itself and is influenced by the metal of a ship as by a small mass of soft iron brought very near to it, are points not certainly ascertained. It is most probable that both modes of action obtain, few days, may be swung around so as to head in a if not others yet undiscovered. We must, there- different direction towards the points of the comfore, depend rather upon actual experiment for pass, and there confined, until the rate in that posi correcting the disturbing influence of the metal tion has been noted; and so on, until the balance upon the rate of a Chronometer, than upon deduc- of the Chronometer shall have occupied all possi tions merely theoretical. It is true that there have ble positions in respect to the magnetic meridian. been proposed methods for counteracting this in- In this way it may be known whether the influence fluence, or eliminating the errors which it produces, upon the balance varies with the direction of the founded more or less upon hypothesis in respect to ship's head, as Capt. Scoresby thinks is the case. the source and nature of its action. Captain Let, then, the Chronometer be brought on shore and Scoresby, for instance, considering the cause of carefully rated in the usual way. It will then be disturbance to arise from the directive influence of seen whether the sea and shore rates are different, the earth upon the balance itself, proposes to neu- and by how much. If there be a difference, then tralize its effect by bringing the balance within the let it be attempted so to place an iron plate in res control of an artificial magnet sufficiently power-pect to the Chronometer on shore, as to reduce ful to keep the whole Chronometer, freely sus- its shore to its previously ascertained sea rate. pended upon gimbols, in the same relative position This mode of experimenting would indeed be de to the magnetic meridian. To say nothing of the fective in some respects. For instance, when a uncertainty of the theoretical view involved in vessel is sailing upon the high seas, its metal would this proposed method of correction, which attri- be brought under the action of a perpetually varybutes to terrestrial magnetism a direct action upon ing force of magnetism; yet, in respect to the nature the balance, so much more energetic than any and amount of influence which a given magnetic which can be exerted by the metal of a ship, as to force will exert upon the balance of a Chronometer, render the latter altogether insensible, it is very very valuable results might be deduced. questionable whether the presence of a powerful magnet will not introduce new sources of disturbance. Mr. Barlow, who has paid a great deal of attention to this subject, thinks that there is danger in this case, of the magnet itself affecting the rate of the Chronometer, not merely by its own action, but by communicating some portion of fixed magnetism to the balance, more than it ordinarily pos sessed. Whatever forces may be exerted upon the arm of the balance by the metal of a ship, their resu!tant will probably lie in the direction of the keel, because in respect to a line running lengthwise the vessel, the metal is symmetrically placed. If the arm of the balance when at rest be placed at right angles with the keel, it is probable that much of the disturbing influence may be neutralized. Mr. Dent in his Chronometrical determination of the difference of longitude between Greenwich and New-York, before referred to, and which you will find in the reports of the "British Association for the advancement of Science," for 1839, seems to Mr. Barlow takes this view of the subject. He is of the opinion that the power of iron to disturb the action of a Chronometer resides in its surface; and he proposes to assign the position of an iron plate in respect to the Chronometer, which have used this precaution, and to this possibly may will produce upon it the same disturbance which will be produced by the iron of the ship. If, then, the Chronometer be rated on shore in the presence and under the influence of such a plate, it is obvious that the rate so obtained is not the shore but be attributed the small difference between the sea and shore rates of the Chronometers which he employed. Yet there was a difference very sensible, and which could not by any means have been neglected in deducing the final result. The existence of a difference at all shows that this mode of cor- the influence of the ship's metal, which is always rection, though very easy of application, is imper- important. fect. Still it is a precaution which ought to be observed on every vessel. In pointing out to you the important uses of the Chronometer at sea, and the delicacy and difficulty of the process of rating one with perfect precision, the necessity of a Marine Observatory will appear obvious, where this service may be performed with attention to every circumstance which is likely to ensure success. After a Chronometer has been rated with reference to the influence of every cause which can affect its motion, if it be a good instrument, it will give for six or eight weeks the longitude of the ship with as much accuracy as "Lunar Distances," and with greatly diminished labor. But occasionally a I proceed to notice another object, which I underChronometer may exhibit sudden and inexplicable stand was had in view, in the erection of the Obchanges in its rate, against which it will be impor- servatory-namely, the construction of Charts. tant to guard. This may be done by having several It would be to little purpose to know with preon board, which is invariably the practice in the cision the place of a ship, unless the ports to be British Navy, and probably in our own. On this reached, and the impediments to navigation to be point, however, I have no precise information. avoided are correctly laid down upon the charts The best Chronometers may now be purchased for employed. If a sand bar, or a coral reef, or other $200 to $250; so that the additional expense of obstruction be incorrectly located, no method of furnishing each vessel with at least three, would be bat small, while the advantages would be very great. Were there but two, a discrepancy between them would be evidence of an error existing in one or the other; but with three, the one in fault could be detected. Further to guard against any influence which may simultaneously affect the rates of all the Chronometers on board, it would be desirable once in two or three weeks to make a careful observation of the longitude by Lunar Distances; not that the result would be more trust-worthy than that of the Chronometers, but their near approximation would be evidence that the Chronometers had suffered no injury and were performing well. finding the latitude and longitude of the ship, however easy and accurate, could ensure its safety. It is just as though the chart was accurate and the ship was provided with no adequate means of determining its own position. It is, therefore, very essential to the Navy, that the charts with which it is furnished should be constructed with the utmost attainable degree of accuracy. From this consideration, it would be altogether impolitic to entrust their publication to private individuals. They might not always feel a sufficient interest in their accuracy; and if they should, they would not possess the means of introducing the various corrections which from time to time are found necessary in Whenever a vessel arrives at a port whose lon- previously existing charts. It would seem, then, gitude has been accurately determined by Solar altogether proper that the charts furnished the eclipses, or by occultations of the fixed stars by the Navy should be constructed and engraved under moon, then it may be certainly known how the the supervision and by the authority of persons apChronometers have performed; and by a careful pointed for this purpose by the government, whose comparison of their results with the known posi- duty it should be to introduce therein the results of tion of the port, the variation in their rates ascer- the latest and best observations. The establishtained. It is, however, always well to make shore ment of a Marine Observatory will greatly faciliobservations, when the vessel is sufficiently long in tate the accomplishment of this object. I have port, to determine the existing rates of the Chro- already indicated, in a general way, the manner in And for this purpose it is desirable that which a vessel should be furnished out, in order to every ship should be furnished with a good porta- determine its position with facility and accuracy. ble transit instrument, which in a single night could But when any particular place is approached, as a be adjusted, so as to give results more accurate harbor, or a cape, or a sand bar, its position bethan those of the sextant and artificial horizon, and comes known by means of the position of the ship, involving much less of calculation. Besides, if and to the same degree of accuracy. In applying, the longitude of the port should not be well ascer- therefore, frequently and skilfully the methods by tained, the transit instrument would be very useful which the position of the ship is determined, the in determining it, by observing the passages, across localities of a great many points become known. the meridian, of the moon's bright limb, and of In this way a vessel may greatly contribute, in a Mars which are near her parallel of declination. single voyage, to the increase of our geographical Such port would serve afterwards as a new point knowledge and to the perfection of our charts. This of departure from which to calculate the place of service it will more effectually render if its Chrothe ship. I must not forget to add, that in rating nometers are carefully rated with reference to their a Chronometer while in port, it will be best to suffer performance at sea, and their going tested from I to remain in its proper place on board, and to time to time by a few Lunar Distances measured carry the time to and from it, by means of a good with the best instruments and with attention to pocket Chronometer. It will thus be kept under every circumstance which can affect the accuracy Bometers. VOL. X-33 |