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peratures, should, if possible, when in high latitudes, keep their timekeepers in a room with the temperature not much lower than 50°; as it is by no means unusual for us to meet with chronometers having rates nearly as steady as can be desired between 60° and 85°, but which will, nevertheless, in temperatures between 30° and 40°, change their rates ten, and even twenty seconds a day. Chronometers intended for constant use in low temperatures, should be compensated exclusively for low temperatures; for with the balance in common use, they cannot be made to go with any degree of satisfaction, through so long a range of temperature as 60° or 80°.

There cannot be a doubt as to the practicability of removing this defect in the ordinary balance, but two things above all others are necessary for its accomplishment. Our means of testing must be such as to satisfy the makers that we can detect at once and without delay any improvement which they may make; and mariners, who are generally the customers of the makers, must make themselves so far acquainted with the defects of chronometers as to show that they can understand and appreciate improvements. The Corporation of Liverpool made the necessary provision for testing chronometers in this port some years ago, and arrangements are now being made in London, under the direction of the Board of Trade, for testing chronometers in a manner precisely similar to that which we have practised for the past ten years. The testing apparatus for London has been made in this town under our immediate superintendence; and an officer has, by permission of the Corporation, been taught our method, in order that the same plan may be adopted in London. No chronometer maker, therefore, either in Liverpool or London, need now be in doubt for more than a few days, as to the efficiency of any improvement which he may attempt in the compensation balance of a chronometer; for the result. of our experience is, that extreme cold is not necessary for the detection of this fault, and the higher temperatures are always under our control. Temperatures below 40° are not favourable for this experiment, unless the fluidity of the oil can be depended on, as a large change in the arc of vibration may render the result uncertain. In testing chronometers for this particular fault, it is however, desirable to elevate the temperature to 100° and upwards, and the oil by being subjected to very high temperatures, even for a few days, may become deteriorated. In the method which we are about to describe, it must therefore be understood that it is only practised at the special request of the maker, who supposes that he has

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effected some improvement in the balance, and who intends to clean the chronometer again after the experiment. Unless this special request be made, 85° or 90° is the extreme heat to which we expose chronometers. This temperature is not greater than chronometers must occasionally be exposed to at sea, and we have found from long experience that no injury whatever is done to the oil by such exposure.

The following is the method of testing for improvements in the com. pensation balance, which we have always found both expeditious and successful. The maker is first requested to adjust the chronometer with the supposed improvement, to go the same in 50° and 80°. The experiment should be repeated several times to insure this being successfully done, and when it is found that changes from 80° to 50°, and from 50° to 80° can be made without altering the rate more than a few tenths of a second, the temperature is increased from 80° to 90°, from 90° to 100°, and from 100° to 110° in succession, and the change through these temperatures repeated two or three times. In chronometers with the ordinary balance the losing rate increases from 80° upwards, till at 110° it is found to amount to several seconds a day; but if the chronometer which is being tested cannot be made to lose more in 90°, 100°, and 110° than it does in 50° and 80°, the balance will be found to be, for all practical purposes, sensibly perfect.* Several chronometers which stood this test at the Liverpool Observatory, were afterwards tested by Professor Bond at the Cambridge Observatory in North America, during a very severe winter. The result was such as to show that when the oil did not become hard or glutinous, the rates of the chronometers remained as steady at several degrees below zero of Fahrenheit as they did in the higher temperatures, scarcely altering more than one second a day in a range of temperature exceeding 100 degrees; but that, if the oil became glutinous or hard, the chronometers, even with this balance, would lose considerably in temperatures below 30°.

Until chronometers used in the merchant service are more generally subjected to a test previous to their being purchased than they now are,

We do not here allude to auxiliary compensations, the adjustments of which depend on the skill of the maker in each individual chronometer. If ever the balance now in use be superseded, it will be by an improvement of such a nature that if the balance compensates at all, the defect which we have attempted to describe will be removed without any additional trouble to the springer.

the makers will for the most part confine their improvements to the chronometers which are sent to the Royal Observatory at Greenwich for trial previous to purchase by the Admiralty. A chronometer sold to the Admiralty gives the maker a name, and this name has till recently been the only guarantee afforded to the merchant captain; hence we often find him in possession of a chronometer, the rate of which is quite as irregular as either of those exhibited in the first three examples.

The makers will exert themselves to the utmost, to supply the astronomer with a good chronometer, because they know that he can test its qualities, and appreciate its value; and that he will not be unreasonable in his expectations. Not that the astronomer is often perfectly satisfied with the performance of his instruments, but he generally makes himself too well acquainted with the failings to which they are liable, to allow himself to be deceived by such imperfections. Now, this is precisely what we wish to see in the mariner. He is called upon almost daily to exercise his judgment as to the degree of confidence which he is justified in placing in his instruments; and a knowledge of the imperfections to which they are liable is the only thing that can guide him to correct conclusions in these, to him, very important matters.

Since the preceding has been in type, I have received a letter from the Chairman of a Committee of Merchants, recently formed in New York, for the purpose of establishing an Observatory in that city, in all respects similar to the Liverpool Observatory, with the exception of the large and elaborately mounted equatorial. Agreeably to the request of the Chairman of this Committee, I have obtained estimates of the probable expense of a Transit Instrument, Sidereal and Solar Clocks, Testing Apparatus for Chronometers, Osler's Anemometer and Rain Gauge, &c., &c., which will be forwarded to New York as soon as possible. We may expect, therefore,

in a short time, to have in full operation a first-rate Nautical Observatory, on the other side of the Atlantic.

The present intention is to confine the business of this Observatory to such objects of practical utility as are more immediately connected with navigation. One or more time balls will be dropped daily, and especial attention will be paid to the rating and testing of Chronometers, for which it is intended to make ample accommodation. Now that the importance of the subject is beginning to be more clearly understood, other sea ports will doubtless soon follow the examples set by Liverpool, London and New York; and there will be no excuse for Chronometers being sent to sea without previously having them properly tested.

ON THE BATTLE OF BRUNANBURH;—AND THE

PROBABLE LOCALITY OF THE CONFLICT.

By T. T. Wilkinson, F.R.A.S., &c., dc.

READ 4TH DECEMBER, 1856.

SECTION I. THE BATTLE.

The Battle of Brunanburh forms one of the most important events in the history of the Anglo-Saxons. The preparations for the conflict exhausted the naval and military resources of the Danish colonists, and its issue consolidated the power and raised the Saxon name to the highest dignity among the states of Europe. Of upwards of 100,000 combatants engaged on both sides, probably the greatest portion perished on the field or during the pursuit; for of the confederated forces led by Anlaf, only a shattered remnant survived to tell the tale of their defeat. At the period of which we speak. Athelstan swayed the sceptre of the Anglo-Saxons with an authority unknown to his predecessors. The Scottish, the Cumbrian, and the Welsh Kings acknowledged his superiority, and those of Northumbria were barely able to maintain their independence. Sihtric, the son of Ingwar, and grandson of Ragnar Lodbrog, was then the reigning King of Northumbria, and Athelstan, during the first few years of his reign, found it necessary to conciliate his friendship by giving him his sister in marriage. The Danish king appears to have inherited much of the ferocity and most of the ability of his ancestors; for the Saxon Annals speak of him as the murderer of his own brother, and in Irish history he is chiefly noted for his piratical depredations. He, however, formally embraced Christianity on the occasion of his marriage, but soon after repenting of his change of religion, he put away his wife and resumed his idolatry. Athelstan determined to revenge this insult offered to his sister, and prepared to invade Northumbria; but Sihtric died before the preparations were completed. Notwithstanding this, Athelstan soon drove Anlaf and Godfrid, the sons and successors of Sihtric into exile, and annexed these counties to his own dominions.

During the struggle for possession, Ealdred was driven from his petty Sovereignty of Bebbanburh; the castle at York, which held out for Anlaf

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