These libraries are interchanged between the stations on the annual visits of the supply-vessels.

Medicine-chests also are furnished to each station.

Medicine-chests.

at English sta

I did not observe any room set apart especially for a work- No work-rooms shop as at our large stations, though keepers are furnished tions. with necessary tools, and their education at Blackwall in mechanical operations would, with the general intelligence possessed by the keepers, make this provision more useful even than in our own service.

A certain amount of standing furniture is provided in Furniture. each dwelling. It includes iron bedsteads, chairs, tables, a desk, &c.

When a keeper is removed from one station to another (either to a better one as a reward of merit, or to an inferior one as a punishment) his family is transported at public

expense.

The keepers at Haisborough, as at all the other stations which I visited, wore the neat uniform of the Corporation of Trinity House.

From Haisborough we steamed out to the Newarp light-, ship, (to be noticed farther on,) and returned after dark to observe from the sea the comparative intensities of the gas and oil lights.

The gas-light is in the northern light-house, the oil-light in the southern, on a point of land nearer the sea, at an elevation 46 feet below the former, the respective heights of focal planes being, as before stated, 140 and 94 feet above the sea. The lower tower is lighted by one of Douglass's four-wick lamps.

The Vestal was stopped at a distance of six and a half miles from the lights, and at a point equidistant from both. The night was clear, and the opportunity for fair-weather observations was excellent. The Trinity House officers on board had directed the keeper of the upper (the gas) lighthouse to burn the ordinary number of jets, viz, 48, till 9 o'clock. At that time the number of jets was to be reduced to 28, and the changes were to be as follows:

At 9 p. m. reduce to 28 jets; at 9.10 p. m. increase to 48 jets; at 9.20 p. m. increase to 68 jets; at 9.30 p. m. increase to 88 jets; at 9.40 p. m. increase to 108 jets; at 9.50 p. m. reduce to 28 jets; at 10 p. m. reduce to 68 jets; at 10.10 p. m. reduce to 48 jets; at 10.20 p. m. reduce to 28 jets; at 10.30 p. m. increase to 48 jets.

Uniform worn by the keepers.

Observation of lights at night.

Memoranda of changes in lights.

serving the

The comparative brightness of the lights was estimated Manner of obby observing them with the naked eye, and also through lights. different thicknesses of red glass. The method of using

using a neutral

the latter was to place successive layers of small plates of glass into frames made for the purpose, until one or both of the lights when seen through them could barely be discerned, and I found that the eye could thus much more readily detect differences between the intensities of the lights than when viewing them without the use of the glass media. Question of I am not, however, satisfied as to the advisability of using tinted glass red glass, since it is probable that those flames which have through which to compare the more of that color in their composition would be placed at a disadvantage, and I would prefer a neutral-tinted glass. Appearance of When we first observed the lights from our position the the lights. gas-light (48 jets) was not equal to the oil-light; between 9 p. m. and 9.10 p. m. (28 jets) it was still more inferior; between 9.10 and 9.20 (48 jets) the same difference was ob served as before; between 9.20 and 9.30 (68 jets) we pronounced the two lights equal.

lights.

obscures

Fog both lights.

At this time a dense fog rolled in from seaward, obscuring both lights, and we steamed toward them till we got within (as we afterward found) two miles of them, both continuing eclipsed. About midnight the fog rolled away, and the lower (oil) light came gradually into view, but when it had apparently attained its full power we could still see no sign of the upper (the gas) light.

Fifteen minutes afterward the upper light dimly ap peared and slowly increased in brightness till about half Superiority of past 12, when both lights were fairly free from the fog, and the gas-lights. in the opinion of all the party the upper (gas) was very much superior to the lower (oil) light.

As the time covered by the instructions given to the keepers had long since expired, it was not until our return Number of jets to London that we learned the number of gas-jets burning, which was then shown to be 108, the number corresponding to the instructions of the keepers for times of dense fog.

burning.

Judgments ar rived at by obser

It was fortunate for our experiment that the fog shut in during our observations. That the oil-light was first to be seen was no doubt due to the fact that the fog rolled in over the land from seaward, (though this was not apparent to us, there being no perceptible breeze,) and that light, being on a point projecting into the sea, was first free from it.

As far as determined by our experiments at Haisborough, vation of lights. I have no doubt the following judgments were correct: 1st. In fair weather the gas-light of 68 jets was equal to the first-order light from the oil-lamp of four wicks as improved by Mr. Douglass.

2d. Neither the light of 28 nor of 48 jets was equal, but that of 108 jets was decidedly superior to the oil-light.