other vessels, which occupies the left-hand page of the log-book, and on the right-hand page a further Register, as follows:

415. The following example of the log of a merchant ship is extracted from the log of the brigantine Tula,* John Biscoe, commander, kept by G. White, mate:

* The Tula and her consort, the Lively, were fitted out by Messrs. Enderby on a voyage of discovery in the Antarctic regions, for the purpose of examining the state of the whale and seal fisheries. I am indebted to those enterprising gentlemen for the above example of a log, which was selected from numerous others on account of its having been kept with unusual care.

Initials of Engineer.

700 00 00 00 00 ∞ ∞ ∞ ∞ ∞

8

68

8

8

10 8

II

8

9

6 2

9

10 6

N.N.W.

S.W.

Steady breezes and fine clear wr.; all

possible sail set to advantage.

4 Steady breezes and do. wr.

gh Do. wr.

Stowed the gaff-topsail.

Ich Fresh breezes, with passing clouds.

Midnight. Increasing breeze and clear wr. 2 In t. g. sail and fore-topmast stud.sail. 3h 30m Passed an iceberg.

4h Strong winds and heavy squalls; carried away the jib boom and split the sail. Took in gaff t. sail. In two reefs in the t. sail and mainsail.

6h A little mod. and clear; set the stayf.sail. Passed an iceberg. 7 Took the bonnet off the g. t. sail and set it.

Noon. Fresh breezes and clear wr.; let one reef out of the topsail.

Lat. obs. 46° 37' S.

Course, N. 19° W. Dist. 189. D. Lat. 18:02. Dep. 615. D. Long. 92. Lat. D.R. 46° 40′ S. Long. D.R. 54° 25′ W.

416. As different plans of keeping ships' logs have been adopted from time to time, we shall repeat here some of the remarks on the subject which have appeared in the preceding editions.

The latitude by D.R. and by observation, and the longitude by D.R. and by observation (chronometer), have been inserted in various ways. Perhaps the most convenient method would be to contract the depth of the horizontal space occupied by the headings "Course," "Distance," &c., and to deepen the next space below them, and then to write the Obs. under the D.R. in both latitude and longitude. In this position they could at once be compared, and, if necessary, the differences taken, as for finding the effect of a current or other purpose.* The longitude by lunar would always be noted in the Remarks, because this cannot be a daily observation

Consistency would require the courses to precede the columns K. and F., because the Course is always spoken of before the Distance; but this may be left to convenience or to custom.

It certainly seems desirable that a systematic method of keeping ships' logs should be universally adhered to. It appears a needless, and is a very perplexing arrangement, that the forenoon should be Saturday, and the afternoon of the same day Sunday. The astronomical day (which is reckoned in this way) has, indeed, for its beginning, the sun's meridian passage at noon, because this is a fact that may be observed, and is taken as a point of departure; and when we have to make astronomical calculations, we of course refer to the beginning of the astronomical day. But surely no satisfactory reason can be given for employing astronomical time for civil purposes, and thus perplexing the common transactions of life by considerations which have nothing whatever to do with them.

In merchant-ships the log is most commonly marked every two hours only; much is thus left to guess-work in cases of alteration of course or wind. But this is not the worst part of the system; for instead of writing against the hours the distance run, the rate for the two hours is written: so that, instead of adding up distances with a reasonable chance of some compensation of errors, the rates are multiplied, with the certainty of doubling the errors of the

estimation.

* Another compartment has been added by some navigators, and appropriated to the effects of the current, as deduced by comparing the ship's place by D.R. with that by observation. The navy log appears complete for these several purposes.

II. THE DAY'S WORK.

417. This is the process of finding the place of the ship, with reference either to her place at yesterday's noon, or to a departure taken since, and comprises.

1st, The Course and Distance made good;

2d, The Lat. and Long. in;

3d, The Bearing and Distance of some port, which is either to be steered for directly, or is an intermediate point of land with reference to which the course is to be shaped, so as to make it or to avoid it.

418. To work a day's work. (1.) Take the courses, with the distance run on each, from the log-board.

When a departure has been taken, consider it as a course and distance in the opposite direction.

If the variation has changed more than 2° since the departure was taken, correct each course separately, No. 224; if not, defer this correction.

Every course affected by leeway must be corrected accordingly. The quantity, if not marked on the board, must be estimated from the circumstances.

When the ship is on the starboard tack, allow the leeway to the left; when on the port tack, allow it to the right, the observer being supposed in the centre of the compass. When the ship is hove-to, take the middle point between that to which she comes up and that to which she falls off, for the compass course, and correc this for leeway.

(2.) Having corrected the Courses thus far, take out to each the D. Lat. and Dep. from the Traverse Tables I. or II., and find the Course and Distance made good by Traverse Sailing, No. 287.

If the variation has not been allowed for, apply it to the resulting course, No. 224.

(3.) Apply the D. Lat. to the Lat. left: the result is the Lat. in, No. 190.

With the Lat. left and Lat. in, and the Course, find the D. Long by Case I. of Mid. Lat. or Mercator's Sailing (No. 315 or 323), unless the Course is due E. or W., when proceed by Case I. of Parallel Sailing, No. 304.

196.

Having the Long. left and Diff. Long., find the Long. in, No.

(4.) Having now the Lat. and Long. of the ship, and those of the port to be worked for, find its Bearing and Distance; if in the Lat. of the ship, by Case II. of Parallel Sailing, No. 307; otherwise by Case II. of Mid. Lat., or Mercator's Sailing, No. 318 or 326; or find the Course on a great circle, No. 337 or 338.

It is mere waste of time to work the Course nearer than to the