I have tried folded blankets in one portion of the ship, but they were worse than the mats, they certainly sopped all the water up, but the bags beneath them drew the moisture all out of them. A wooden deck will not retain moisture like an iron one.

The system of loading a cargo in Rangoon is, to lay down five heights of bags fore and aft the hold, then parallel to the keel, and midway betwixt the centre line and the sides, to place wooden ventilators on edge (supplied by the shippers, as well as ventilator boards) at right angles to them, and about five paces apart others are laid from side to side, intersecting the fore and aft ones, and all opening into each other; then vertical ones are placed having their lower ends resting on top of one of the junctions, and their upper ends placed inside the ship's iron ventilators, others are placed at the four corners of all hatchways.

Then, up and down the midship stanchions, fore and aft the ship, ventilator boards are lashed, one on either side, and kept a little apart, so that when the ship is loaded you can stand in the upper hatchway and look down through the slit betwixt the boards to the keelson.

After the first tier of ventilators are in, work goes on again until other five tiers have been added, then come more ventilators, and so on till the ship is full.

Some of the rice shippers at their own expense mat the top of the bags fore and aft to prevent them getting soiled.

A bag with 220lbs. of grain in it is bulky, and as they are pretty tightly filled it will settle down considerably; so much so, that although stowed close up to the beams in Rangoon, a small boy could crawl fore and aft the cargo in the channel; therefore you will find that if your ship is carrying a press of sail coming across the north-east Monsoon, the cargo will settle to port, and if your coals are burned evenly off each side you will have a considerable list that way by the time you reach Aden.

The settling is most rapid the first week out, after that it gets slower, and if you have light winds at the commencement of the voyage it may not amount to much afterwards.

I know one steam company which makes it a rule that each of heir vessels is to have a margin of 100 tons coal above the esti

mated consumption to reach the various ports. The comfort conveyed to all on board must be incalculable, for with plenty of coals in the ship you can trim her any way you like.

What anxiety the man must have nearing home whose ship has a strong list to port, while a gale of wind is blowing on the starboard beam, and all the coals in the starboard bunker. If the ship were fitted with water-ballast tanks, of which the port and starboard ones were independent of each other, the desperate venture might be tried to fill one of the weather ones. It might succeed, but while it was filling, what a fearful risk lest, when it was half full, the mass of water rushing from side to side might render the vessel unmanageable and cause her to founder.

With a ship divided into three cargo compartments, two large and one small, and with four ventilators in each of the large ones, the heated air will always be found struggling to windward.

Going head to wind, if the two foremost ventilators be turned with their mouths facing the wind and the two at the rear of the hold turned from it, a quantity of heat will be found coming up the after ones, but not much; reverse the process, and you will be astonished at the rush which will come up the forward ones. In like manner, if the wind be off the starboard side, the heat will all cling to that side; this will be more perceptible in cold weather, as you will find drops of sweat clinging to the deck and beams on the weather side, while down to leeward will be dry. Be very careful in taking off hatches in cold weather, as you are likely to do more harm than good. The moment the hatch is off a burst of heat comes up, but this is succeeded by a rush of cold air down, and if there has been any sweat gathering on the under side of the deck it will quickly develop into large drops and rain down on the cargo.

Frequently more harm is done the first day you begin to discharge in the docks than what has been done all the voyage, for the sudden opening of all the hatches to get the cargo out lets in such a rush of cold air that sweat drops form on every particle of iron within its influence, and a long roll of first class damages. are added to the list, which on a warm day might have been slight.

Use every endeavour to prevent wet or damp bags coming on board. Boatmen are not over careful in handling buckets of drinking water. If through negligence a wet bag comes in you will find it again on arrival home, and its position well defined by a ring of damaged bags round it.

Shippers will only accept clean receipts, therefore you are at perfect liberty to reject any bags you may be suspicious of.

Towards the end of the season there is not so much risk of your cargo heating, as paddy coming from far distances inland, and arriving late, is much drier than that grown near at hand, and placed in the market soon after the harvest.

Besides, a late cargo is often a mixed one, for, when the first rush is past, and the mills only working regular time, quantities of "white rice are made for the Continental markets, so that a cargo may consist of white rice, "coodie" or broken rice, cargo rice, and rice meal. Coodie is the heaviest, white rice next, then cargo

rice, and lastly the meal.

A sailing ship is ventilated differently to a steamer. Having but one hold, the small ventilators would not be sufficient. The system is, to stow in five heights fore and aft, then midway between the centre line and the side, to strip out one row of bags from end to end, and at intervals single rows athwartships; this leaves broad, deep gutters, fore and aft and across. These are bridged over with bits of wood, then more cargo is stowed in until the next series of gutters is to be formed, and so on till the cargo is loaded; this secures good ventilation through the ship.

Some ships omit the athwartship gutters altogether. Great care is requisite in taking in the cargo, to sew up any bags that may burst, at once, as loose rice getting into a gutter, or ventilator, will check the circulation of air, and hinder the clear ones from doing their duty as they ought.

If, through keeping your hatches off for ventilation, a spray should find its way to the bags, mark the wet ones before putting the hatches on; the first fine day get them up on deck, open them out and thoroughly dry the contents, and re-bag it. Never mind whether the bags are discoloured when you get home. Tell nkly how it happened, as the rice will have to be milled over

and over again; the grain will not be any the worse if dried quickly.

Never think of leaving wet bags to rot in the hatchways, while you trust to your log book and protest to get you out of the scrape.

J. McKIRDY.

ON COMPASSES, AND THEIR ADJUSTMENT IN

IRON SHIPS.

(Continued from p. 650.)

T may be as well to take a summary of results, and add a few notes.

Every bar magnet or magnetised needle has two

poles, one of which differs in quality or property from the other. One is the north seeking, or red pole, and the other, which is directed towards the south, is called the blue pole. Like poles repel, and unlike poles attract, each other.

The position of the poles is not at, but a short distance within, the ends of the magnet, generally about a twelfth of the length of the bar from the ends; but the thinner the bar the more nearly do the poles approach the ends.

Permanent magnets are made of the best steel, which should be perfectly hard throughout the length of the bar, and the steel which is most likely to retain its magnetism unimpaired is that which, when magnetised, developes the greatest power.

A horse-shoe magnet is only a bent bar magnet.

There are various methods of magnetising steel bars or needles, by single touch, or double touch, but the best and most expeditious way is to place them within the coil of a voltaic battery.

There is a limit to the magnetic power of every steel bar or needle, and when it has taken its full dose it is said to be magnetised to saturation; but in time it is sure to lose a portion of its magnetic power.

The bar magnets used in adjusting ships' compasses are cased in brass or copper, but the latter metal is the best for the purpose.

Steel and iron of all kinds may become magnetic by induction— by being in juxtaposition with permanent magnets, or through the earth's magnetic influence-but all kinds are not equally susceptible. It is only soft iron which instantaneously acquires, by induction, magnetic properties, and as quickly loses them on removal of the cause, or by change of position. Standing vertically, or nearly so, the effect on the compass of vertical induction in soft iron is the same as that of a permanent magnet; when horizontal, its effect in one sense is diminished, but its influence on the compass is then most detrimental, since it interferes with the directive force of the needle.

Hard iron, however, has a capacity for the reception of magnetism through continuous and heavy hammering; it is equally capable of retaining it, but in diminishing amount, after the exciting cause has ceased, and its character is never wholly lost. This has necessitated a new name. "The magnetism of a struck iron bar resembles the magnetism of a permanent steel magnet in all respects but this, that, while perhaps no change can be remarked in hours or days, it infallibly diminishes in a long time. To express this partially permanent character, the term subpermanent magnetism' has been adopted. In single bars, the subpermanent magnetism diminishes sensibly in a few hours, and is lost in a few days. In some large iron ships, a portion of it has remained unaltered for many years. It would seem that where the operation of magnetising by hammer-blows has been rapid, the magnetism is not very firmly fixed; but where the violence has been long continued, the magnetism is so firmly established as to become an immovable quality of the iron."-Sir G. B. Amy's Treatise on Magnetism.

The effect of the earth's magnetism on the compass needle is merely directive.

The direction of a freely suspended magnetised needle-that is of a needle free to move horizontally and vertically-is the visible pression of the direction of the earth's magnetic force; and