of the Barometer, for several days previous, in your mind; be very cautious when the mercury is low, even though it be rising; and remember that it is better to be prepared for a storm many times too often than once too seldom.

MANAGEMENT OF THE BAROMETER.

Before fixing the Barometer in its place, it should be carefully examined to see if any air exists in the "vacuum" above the mercury. Somewhat suddenly incline the Barometer till the mercury runs to the top of the tube with a slight jerk; if it does not tap sharp, there is some air present. To eject it, invert the Barometer and gently strike it with the hand this will drive the air-bubble up into the cistern.

The Barometer should be hung in gimbals, and so as not to swing too freely. It must be out of the sunshine, but in a good light for reading, as near midships as possible, and out of the reach of gusts of wind and sudden changes of heat.

In reading it at night, a piece of white paper should be placed behind the glass, (if the construction admits of it,) and a strong light behind the paper.

In making an observation, give a few gentle taps to the glass; set the index of the vernier to the upper surface of the mercury, being careful to hold the eye level with the top of the mercury, so as not to set the vernier too high or too low. If the top of the mercury appears arched, the vernier should be set to the top of the arch.

If the instrument is a "Kew Marine," with the amount of corrections furnished, apply the correction to obtain the true height of the mercury. If, however, the glass is one of the ordinary kind, the owner should have it compared (before leaving port, and after returning) with some standard, and the error of the scale ascertained. Ordinary ship Barometers, as frequently furnished, differ so much in the "set" of their scales, as to render observations by them valueless for comparison, unless this precaution be attended to.

The exact height of the cistern above the ship's water-line should also be known and recorded, and the Thermometer, attached to the Barometer, should be read at every observation.

Aneroid Barometers, when carefully constructed, are valuable substitutes for the Mercurial; but Wheel Barometers are valueless as scientific instruments.

Every ship-master should have a good Thermometer, (or heatmeasurer,) besides that attached to the Barometer, for the purpose of recording the temperature of the air. It should be kept freely exposed to the external air, (not in the cabin,) out of the reach of direct sunshine, and away from warm regions, such as the engine-room or fires; as far as possible from any substance likely to become warm in the sun's rays; its bulb should never be wetted by rain or spray, and at night it should be screened from the sky. In reading it, the observer should avoid touching or breathing on it, or in any way warming it, as by a light.

Besides its general uses, the approach of icebergs, even when many miles away, is frequently shewn by an extraordinary fall of the Thermometer. Observe, that the Thermometer rises for heat and falls for cold. 32° is fresh-water freezing point, and 60° is the measure of a comfortable degree of warmth.

The weather-science (Meteorology) is in a very imperfect state. Seamen are strongly urged to keep careful readings of the Barometer and Thermometer, and to note the direction and force of the wind, with the appearance of the sky, &c., even though they trade only on our home seas, for here, as elsewhere, much remains to be learnt, and Meteorology is one of those sciences which grow only by reasoning upon observed facts.

To further this end, the best times for observation are 3 and 9 a. m., 3 and 9 p. m., or 3, 6, 9 a. m., noon, and 3, 6, 9 p. m., midnight. Hourly observations are much required at the following times on the 21st of each month, particularly March, June, September, and December; also when becalmed, especially near the Equator; during threatening weather and gales, and for some time after they have passed; when the sky suddenly clouds over, or fogs form unexpectedly; and when any unusual rise or fall of the mercury takes place.

The localities, tracks, nature, and appearance of the so-called "circular hurricanes," with the movements of the Barometer and Thermometer in connection with them, require much careful observation and unprejudiced discussion before they will be so thoroughly understood that the seaman will, in every case, cope with them successfully.

In promoting all this, the seaman has a strong personal interest; and, remembering that careless or inaccurate observations are worse than none, he should strictly comply with all the suggestions herein contained.

Communicated by J. Bolam, Head Master, Board of Trade Nautical Schools, Leith.

LOG LINE.

The Log Line is used to denote what distance a Ship runs, and the length of a knot on it must bear the same proportion to a nautical mile as the number of seconds in which the glass runs does to the number of seconds in an hour.

The practical rule for finding the number of feet and inches is-Add a cipher to the number of seconds in which the glass runs, and reckoning this as feet, divide by 6; the remainder multiplied by 2 will give the inches.

Always allow sufficient stray line, say about 12 fathoms.

LEAD LINE.

The Lead Line has nine marks and eleven deeps, marked as follows:

The Deep-sea Lead Line is marked in the same way as far as 20 fathoms, after which a knot is placed for every additional 10 fathoms; that is,

Every 5 fathoms is marked either with a single knot, or (which is preferable) a piece of leather.

LLOYD'S RULES

FOR THE

STOWAGE OF MIXED CARGOES,

Prepared by HENRY C. CHAPMAN & Co., Agents for Lloyd's, Liverpool.

1.-Owners, Commanders, and Mates of Ships, are considered in law in the same situation as common carriers. It is therefore necessary that all due precautions be taken to receive and stow cargoes in good order, and deliver the same in like good order. The law holds the Shipowner liable for the safe custody of the goods when properly and legally received on board in good order, and for the "delivery" to parties producing the bill of lading. The Captain's blank Bill of Lading should be receipted by the Warehouse Keeper, or person authorised to receive the contents. Goods are not unfrequently sent alongside in a damaged state, and letters of indemnity given to the Captain by the Shippers for signing in good order and condition; this is nothing more or less than conniving at fraud. Fine goods are also often damaged in the ship's hold by Lumpers, if permitted to use cotton hooks in handling bales. All goods must be received on board according to the custom of the port where the cargo is to be taken in; and the same custom will regulate the commencement of the responsibility of the master and owners.

2.-HEMP, FLAX, WOOL, and COTTON, should be dunnaged 9 inches on the floors, and to the upper part of the bilge; the wing bales of the second tier kept 6 inches off the side at the lower corner, and 2 inches at the sides. Sand or damp gravel ballast to be covered with boards. Pumps to be frequently sounded and attended to. Sharp-bottomed Ships one-third less dunnage in floor and bilges. Avoid Horn Shavings as dunnage from Calcutta.

3.-All CORN, WHEAT, RICE, PEAS, BEANS, &c., when in bulk, to be stowed on a good high platform, or dunnage wood, of not less than 10 inches, and in the bilge 14 inches dunnage; the pumps and masts cased, to have strong bulk-heads, good shifting boards, with feeders and ventilators, and to have no

admixture of other goods. Flat-floored, wall-sided ships should be fitted with bilge pumps. On no consideration must the

staunchions under the beams be removed.

4.-OIL, WINE, SPIRITS, BEER, MOLASSES, TAR, &c. to be stowed bung up; to have good cross beds at the quarters (and not to trust to hanging beds,) to be well chocked with wood, and allowed to stow three heights of pipes or butts, four heights of puncheons, and six heights of hogsheads or half-puncheons. All Moist Goods and Liquids, such as SALTED HIDES, Bales of BACON, BUTTER, LARD, GREASE, CASTOR OIL, &c. should not be stowed too near 66 Dry Goods," whose nature is to absorb moisture. Shipowners have often to pay heavy damages for leakage in casks of Molasses, arising from stowing too many heights without an intervening platform or 'twixt decks. From Bengal, goods also are frequently damaged by Castor Oil.

5.-TEA and FLOUR, in barrels; FLAX, CLOVER, and LINSEED, or RICE, in tierces; COFFEE and COCOA, in bags; should always have nine inches at least of good dunnage in the bottom, and fourteen to the upper part of the bilges, with 2 inches at the sides; allowed to stow six heights of tierces, and eight heights of barrels. All ships above 600 tons should have 'twixt decks or platforms laid for these cargoes, to ease the pressure; caulked 'twixt decks should have scuppers in the sides, and 2 inches of dunnage laid athwart ship, and not fore-and-aft ways, when in bags or sacks; and when in boxes or casks, not less than one inch. RICE, from Calcutta, is not unfrequently damaged by Indigo, for want of care in stowing.

6. Entire Cargoes of SUGAR, SALTPETRE, and GUANO, in bags, must have the dunnage carefully attended to, as laid down for other goods. TIMBER ships are better without 'twixt decks, if loading all Timber or Deals. Brown Sugar to be kept separate from White Sugar, and both kept from direct contact with Saltpetre.

7. Por and PEARL ASHES, TOBACCO, BARK, INDIGO, MADDERS, GUM, &c., whether in casks, cases, or bales, to be dunnaged in the bottom, and to the upper part of the bilges, at least 9 inches, and 2 inches at the sides.

8.-MISCELLANEOUS GOODS, such as boxes of CHEESE, kegs and tubs of LARD, or other small or slight-made packages, not intended for broken stowage, should be stowed by themselves, and dunnaged as other goods.

K