to four times that of the lighthouse. Three men are sufficient for a rock lighthouse-a lightship requires eleven men. The annual cost of maintenance of a first-class lighthouse in England is from £265 to £340; in Scotland, £380; and in Ireland from £400 to £490. The annual cost of maintenance for a lightship is in England from £1100 to £1200; and in Ireland from £1200 to £1350.

Dutch vessels, the fishing schuyt and the sturdy galliot, have ever been celebrated for riding safely in foul weather, and particularly for riding safely when at anchor; and it was for this reason that in the last century Dutch galliots were frequently purchased for conversion into lightships, and even at the present day the lines of the most scientifically designed light-vessels are still founded on those adopted by the Dutch shipbuilders of two hundred years ago.

In the last century the Trinity House owned but five light-vessels-the Nore, the Dudgeon, the Owers, the Newarp, and the Goodwin. At the present time this country possesses in all sixty-two lightships, and Ireland eleven; and out of this number sixteen are placed around the mouth of the Thames, and seven are in the estuary of the Mersey; the oldest lightship on the British coasts, and probably the oldest lightship in the world, being the Nore light at the entrance of the Thames, a light-vessel having been first placed here in 1732.

All the light-vessels belonging to the Trinity House are painted a dull red, and have their names, as the Nore, the Gull, or the Mouse, painted in white letters on the side; on the Irish coasts the lightships are painted black, with a white ribbon. All light-vessels show a bright riding-light on the fore-stay at a height of six feet above the rail, to show the direction in which they are riding.

In spite, however, of the fact that some of the modes of illumination that are adopted in the fixed lighthouse ashore, cannot be made available in the case of the light-vessel afloat, yet every means is taken to render the light-vessels thoroughly efficient, and out of the seventy-three lightships around the coasts of Great Britain and Ireland, sixty show either revolving or flashing lights. The reflector system is invariably adopted

for lightships, the parabolic reflectors being similar to those in the lighthouses, but smaller, being only 12 inches in diameter. For fixed lights eight lamps and reflectors are generally used, one lamp occupying each angle of the octagon-shaped lantern; for revolving lights, the number of lamps varies from four to eight, the lamps being all hung on gimbals to ensure their preserving a vertical position during the rolling of the vessel. In occulting lights, instead of the lantern itself revolving, a shade or "eclipser" is passed in front of the lamps. In the case of an ordinary revolving light, when viewed from a distance, the light begins faintly, increasing in brilliancy until it reaches its brightest, and then as gradually declining. This arises from the gradual revolution of the lamps allowing the light to be seen before the actual line of axis of the light is presented to the spectator. In the case of occulting lights, where the "eclipser," or shade, is suddenly passed across the lamps, the flash of light is shown instantaneously, and as instantaneously extinguished. The flickering of the light when seen from a distance, caused by the interposition of waves, is perhaps more apparent in the case of a light-vessel than in that of a lighthouse, the light shown by the former being lower down to the level of the water than is the case with the latter.

The value of electric lighting afloat has not as yet been conclusively proved. The experiment recently tried on the lightship in the Mersey was anything but successful. It is held by many seamen of the old school that a "dazzling, blinding" light is by no means desirable, while the electric flash-lights, or so-called "lightning lights," exhibited from one of the towers on Cape La Hève, are open to many objections. The lighting apparatus is four-sided, and the intensity of the beam is stated to exceed twenty millions of candles, each flash lasting only one-tenth of a second, and being repeated every five seconds. With this the main defects are-first, the inequality in the intensity of the flashes when the largest carbons are in use; secondly, the rapid decrease in the intensity of the light as the distance from it increases; thirdly, the cessation of the "lightning" effect at long ranges. Our own St. Catherine's light, visible at twenty-three miles,