clean water, and, after having stirred it up well with a stick, let it rest for a few moments; then pour off the liquid mixture into another vessel carefully, to separate the small gritty particles which it may contain, and which, by this means, will remain at the bottom of the first vessel. That being done, leave it to settle about half an hour, when pour off the water until the rouge appears on the edge of the vessel.

This liquid rouge must be spread lightly, by means of a pencil or piece of soft linen, over the entire surface of the glass to be cleaned. When this coat of rouge becomes dry, rub it with a piece of buffskin until all of it is entirely removed.

The rouge thus prepared should be entirely consumed, as it will be unfit for future use for cleaning.

SPANISH WHITING.

XXXII. The Spanish whiting in habitual use for cleaning the glass of the lantern and the silvered portions of the reflectors must be prepared in the same manner as the polishing rouge, but in larger quantitities, according to the necessity.

GLAZING.

XXXIII. The glazing of the frames of the glass and all the joints of the lantern through which the rain may penetrate ought to be attended to with the greatest care.

XXXIV. The putty employed should be composed of three parts of Spanish white and one part of white lead, both well pulverized and reduced to a paste a little stiff, and well beaten up with equal parts of boiled and common linseed oil.

TO REPLACE THE GLASS.

XXXV. As the keepers of beacon-lights may be required to replace a broken pane of glass, it may not be amiss to enter into some details on the subject. Having unscrewed the slats, and removed the pieces of broken glass, the old putty must be carefully cleaned from the frames.

Try the new pane of glass, to see that it will not touch any part of the frame, and that there will be a play of about one-twelfth of an inch all around, and particularly around the notches made to the right of the bolts fixed to the uprights.

If any portion of the glass touches its frame, it must be carefully and gradually removed by using a pair of glazier's pincers. Having done so to all parts of the glass which do not fit, the necessary dimensions will be obtained.

A coating of spirits of turpentine must be spread on the frames, and the putty is then applied. Three small blocks of soft wood, of about one-twelfth of an inch in thickness, are to be placed between the lower border of the glass and the frame, one being situated in the middle and the other two at about two inches and a half from the uprights. Without this precaution, the weight of the glass would start the putty, and it would come in contact with the hard surface of the lower border of the frame. Blocks of the same thickness must be placed on the putty

throughout the whole length of the uprights, and between the vertical edges of the new pane and the edges of the two adjacent ones. The slats must then be replaced and the putty applied.

The putty must not project beyond the perpendicular and upper slats, but it is to be bevelled along the lower one, so as to permit the water to run off.

CATADIOPTRIC APPAaratus.

XXXVI. Should any of the putty of the rings or prisms of the apparatus be started, it must immediately be replaced with new putty, in the manner already explained.

Once each month the glasses must be washed with spirits of wine. The apparatus must be cleaned once a year with polishing rouge. This must be done as described in article 31.

METALLIC REFLECTORS.

XXXVII. The parabolic and sidereal reflectors must be wiped at first with a soft linen to remove the dust, then rubbed with a buff leather designed for this purpose until their polish is restored.

At the end of every two months these reflectors must be polished with Spanish whiting, and the precautions indicated in article 39, must be observed during this operation. It is the more essential to use these precautions, as the polish of silver is much more easily affected than that of glass.

LAMPS.

XXXVIII. At the end of every fifteen days the service lamp of the lighting apparatus must be removed and replaced by one of the spare lamps.

CONSTANT LEVEL LAMPS.

XXXIX. Should a burner be injured by use or accident, it must be replaced immediately by one of the spare burners. This can easily be done by unscrewing the junction joint. Before placing the new burner, the junction must be furnished with a leather washer.

LEVEL OF THE OIL.

XL. The level of the oil in the new burner must be attended to; it must be maintained at about one-twelfth of an inch below the upper edge. Should the level be too high, the oil would overflow; if, on the contrary, it be too low, the flame would be too near the burner, whose edges would soon be burned. When the level of the oil is too high, a small plate of tin must be soldered over the notch on the small cylinder at the bottom of the reservoir of the lamp; then, with a file, a new notch is made to the cylinder, care being taken not to make it as low as the first. When the level is too low, the notch is enlarged in the manner above stated.

CLEANSING.

XLI. All the brass work of the service lamp must be cleansed every eight days with tripoli dissolved in spirits of wine. When a lamp is withdrawn from the apparatus to be placed in store, its wicks must be removed, the lamp emptied and drained, and cleansed outwardly with tripoli. It is cleansed inside by rinsing it several times with boiling water, or a weak lye of ashes.

CONSTANT LEVEL LAMP.

XLII. The body of the pumps of the lamps and the outside of the burners must be cleansed at the end of every eight days with Spanish whiting mixed in a little oil.

When the inside of a lamp or of a burner is clogged with oil, it must be cleansed in the manner just stated.

MODERATOR LAMPS.

XLIII. At the expiration of every eight days the exterior of the lamps must be cleansed with tripoli mixed with spirits of wine, and the small filter of metallic cloth below the burner must be removed and washed with boiling water.

When a lamp is removed from the apparatus to be placed in reserve, the wick must be withdrawn and the oil poured on the filter; the machinery is then slightly wound up, and the lamp reversed over the drain.

The outside of the lamp is rubbed with tripoli, and the burner cleansed.

HYDROSTATIC LAMPS.

XLIV. The principal care required for a hydrostatic lamp is to keep it constantly clean.

The burner, the chimney holder, the neck, the body of the lamp, and the draining cup, must be cleansed daily.

The same with regard to the stopper of the burner and of the stopper of the funnel.

When a lamp, after being used fitteen days, is withdrawn to be placed in reserve, a wire must be passed through the air tube to remove any particles of crystallized sulphate which may have been formed there. Should this tube become clogged, the oil could not reach the burner. Should the lamp, in consequence of the crystallization of the salt, or from any other cause, cease to work properly, by the following process it can be cleansed:

1stly. The air tube is removed in order to drain the oil into the cup. 2dly. When the drainage has ceased, the lamp is reversed to empty out the oil and liquid sulphate; the stopper placed at the bottom is removed, and the remainder of the oil and liquid is received in a vessel with a large mouth. When the lamp is entirely empty, the stopper is replaced.

3dly. The lamp must be rinsed several times with boiling water, and shaken in every direction, until it is ascertained that no crystallization remains in it. The lamp is then emptied and drained.

4thly. The oil is separated from the solution of sulphate of zinc, and both the specific weight and volume of the latter are ascertained by means of the areometer and the tin measure gauged to contain the quantity necessary for one lamp. The density and volume are augmented, if necessary, by dissolving some crystallized sulphate in a small quantity of hot water, which is afterwards poured slowly into the measure. Should the liquid become too heavy, a small quantity of pure water is added to it; if, on the contrary, it be too light, some concentrated liquid sulphate is added to it.

When the weight and the volume have been ascertained to be correct, the liquid is poured into the lamp by the orifice of the leather box, whose air tube has first been removed.

The lamp will be supplied with oil in the manner described in article 18; then it must be placed in reserve to await its turn of service.

CLEANSING THE GLASS CHIMNEY.

XLV. When the chimney of a lamp is stained with cooked oil, the spots are removed by rubbing it with a cloth dipped in oil; then it is wiped with care, and rubbed with Spanish whiting.

REVOLVING MACHINERY.

XLVI. The revolving machinery of moveable lights is cleaned and kept in order in the following manner:

Every morning the cage, the wheel communicating the movement, and that of the carriage must be dusted.

The large vertical rollers, the small horizontal rollers, as well as the railway on which they run, must be wiped off.

Every eight days these rollers must be removed, their axles wiped, a small stick covered with linen passed through the openings which receive them, and a small quantity of clockmaker's oil poured into them before they are replaced.

Care must be taken not to remove more than one roller at a time. Occasionally the pivots of the machinery must be lubricated with clockmaker's oil.

Yearly, in July, the revolving machinery must be taken apart by the keeper to be thoroughly cleansed.

To cleanse the brass parts of the machinery, their surfaces are coated with tripoli mixed in spirits of wine, and they are then rubbed with a small soft brush until they receive a fine polish.

Should it be found impracticable to remove any stains with the brush, a small spatula of soft wood and tripoli must be used for this purpose.

The iron and steel parts must be rubbed with a spatula of soft wood dipped in oil.

A stick covered with a piece of linen may be used to cleanse the holes of the pivots of the axles, as well as the screw holes.

Before putting the machinery together again, a small quantity of clockmaker's oil must be poured into the holes in which the axles work, and all the different parts of iron and steel coated with tallow.

CLEANSING OF THE INSTRUMENTS.

XLVII. All the tin utensils used in the light-house service must be rubbed with Spanish whiting twice a year, or oftener if necessary.

NOMENCLATURE AND USE OF THE UTENSILS USED IN LIGHT-HOUSES.

FILTER.

XLVIII. The oil used in the lamps of light-houses must be filtered by the keeper.

The filter is in two parts; the upper part contains the filter, properly so called, and the lower part is a reservoir to receive the filtered oil. The filter consists of a tin plate pierced with holes, over which is placed a piece of cloth and a layer of fine sand about one-tenth of an inch in thickness.

Once a month the cloth must be washed with hot water and soap, and the sand passed through boiling water. They must not be again used until they have been perfectly dried; to effect this, the sand must be dried over a fire.

Care must be taken not to use sea sand, even after it has been washed in fresh water.

SERVICE BASKET.

XLIX. The service basket is in the form of a box, with a handle and cover in two parts.

It is divided into three compartments. The smallest contains a flat box to receive the greasy cloths and ends of wicks; under this box are placed clean cloths used in wiping the glasses.

In the second part are placed one or two spare chimneys.
The third part must contain the following articles:

TRIANGULAR SCRAPER.

A triangular scraper, used to remove cooked oil from the edges of

the burners.

BOTTLE-BRUSH.

A horse-hair brush to cleanse the inner air tube of the burner.

CURVED SCISSORS.

Curved scissors to trim the lamp-wicks.

CALIBRE.

A calibre of tin, curved at its extremity, to enable the keeper to cut

the wicks the proper length.