The second of two articles by David Stevenson F.R.S.E Member of the Institute of Civil Engineers, describing the building of lighthouses. Published in 1860 for the Good Words magazine.

The last number of “Good Words” contained a brief sketch of the history and construction of Lighthouses. What has been said will, we trust, satisty our readers that, in spite of physical and engineering obstacles, lighthouses have been built on the pinnacles of sea-girt rocks however high and precipitous, and on the rugged surfaces of shelving reefs however low and wave-swept; and we feel confident, that whenever a sunken reef can be shown to have led our goodly ships to destruction and their hardy crews to their grave, our Lighthouse authorities will not shrink from the responsibility of founding a light-tower on it in the face of all difficulties. Having explained the construction of some of those important engineering works which serve as beacons and landmarks by day, we have now to endeavour to show how they serve the far more important object of guiding the seaman by night.

In early times this problem was solved in a very off-hand manner. The light towers of the last century, designed and executed in accordance with the highest engineering skill, however useful by day, were, after all, most imperfect guides to the benighted mariner. Indeed the rude expedients adopted at that carly period to give light to the sailor in a dark and moonless sky present a very curious contrast to the careful attention which has been bestowed on lighthouse illumination by modern philosophers and engineers. If proof of this be wanted we have only to refer to the twenty-four miserable candles which, unaided by reflectors or any other optical contrivance, shed their dim and uncertain light from Smeaton’s famous Eddystone for nearly half a century after it was built. But, indeed, all lights had not even the advantage of the glazed lantern which protected the candles of the Eddystone;-the grand Tour de Cordouan was originally lighted by blazing fagots of wood burned in an open chauffer. And many of the early Lighthouses were open coal-fires. On the Isle of May, at the entrance to the Frith of Forth, a coal-light of this rude description was exhibited for the long period of 181 years; and, as it may be regarded as a model of the lighthouse of days now passed away, it may not be uninteresting to give a short account of it.

The Isle of May was originally a private light, the right of levying tolls on shipping being vested in the owner of the island. It was the only instance of the kind in Scotland, but there were many similar cases in England.

The Commissioners of Northern Lighthouses, considering that it would be advantageous to the public that so important a light should be placed under public management, so that the shipping might not only have a better light but be saved the high passing toll charged by the proprietor, entered into treaty with the Duke of Portland, the owner of the island, for the purchase of his rights.

A bill was accordingly introduced into Parliament in 1814, authorising the purchase of the Isle of May, with the right of levying toll, for the sum of 60,000l. So soon as the property came into the hands of the Commissioners they erected a new lighthouse, and on the 1st of September, 1816, the old chauffer was discontinued, and a light from oil with reflectors was exhibited in its stead. We are enabled, from an old plan in our possession, to present the reader with a sketch (fig. 1) of the original chauffer light of the Isle of May, with its pulley and box for raising the fuel to the top of the tower, and its inscription stone above the door bearing the date of 1636. The consumption of coal in this open chauffer was latterly about 400 tons per annum. It was one of the best coal-fires in the kingdom, and three men were employed to keep the bonfire burning, so that its inefficiency as a light was not due to any want of outlay in its support. But its appearance was ever varying: now shooting up in high flames, again enveloped in dense smoke, and never well seen when most required. When Mr. R. Stevenson visited the island, with a view to its purchase by the Commissioners, he was told by the keeper, that in violent gales the fire only kindled on the leeward side, and that he was in the habit of putting his arm through the windward bars of the chauffer to steady himself while he supplied the fire with coals, so that in the direction in which it was most wanted hardly any light was visible! Nothing can be worse than any variableness or uncertainty in the appearance of a light. Better far not to exhibit it at all, than to show it irregularly; and the coal-lights were so changeable and destitute of characteristic appearance as to be positively dangerous. This indeed was too sadly proved by the loss of H.M. Ships “Nymphen” and “Pallas,” which on the 19th December, 1810, were wrecked near Dunbar, the light of a lime-kiln on the coast of Haddington having been mistaken for the coal-light of the Isle of May. Fortunately only nine of their crews of 600 men perished; but the vessels, valued at not less than 100,000l., became total wrecks.

But these early lights, which were variable in strength and destitute of a proper characteristic appearance, had other disadvantages, for unfortunately they sent the same amount of light up to the sky and down upon the ground as they shed upon the sea; and inasmuch as it is from the sea only that a lighthouse requires to be viewed, it is obvious that most of the light from these great bonfires was utterly lost to the mariner, for whose use their flames were nightly fed by tons of coal or piles of timber. Now the idea of collecting these stray rays from their useless illumination of the sky and of the ground, and, as shown in fig. 2, throwing them into a direction that would give more light to the sailor, formed the commencement and is the object of lighthouse optical engineering.

What we mean may perhaps be made more clear by the aid of a diagram. A lighted candle (fig. 3) sends forth its naturally diverging rays as shown by dotted lines in all directions, lighting up the whole roof, floor, and walls of the chamber in which it stands; but on placing behind it a reflector, a, b (fig. 4), we are enabled, by adjusting it to the focus, to collect all the rays that fall upon the surface of the reflector, and to throw them forward, as shown by the parallel lines, so that the light which formerly passed backwards and was expended in lighting the chamber, is thrown in the opposite direction and forms a beam of light of great intensity, because of the greater number of rays transmitted, and there-fore, if shown towards the sea, it will be more useful to the mariner than the naturally diverging rays from the unassisted flame of the candle. This was the first step in what is called the catoptric* or reflecting system of illumination.

Again, instead of placing a reflector behind a light, the same object may be obtained by placing a lens, a, b, in front of it, as shown in fig. 5. In this case the lens has the effect of refracting, or bending all the rays im pinging on it into the direction shown by the hard lines, thus collecting the stray rays and sending them forward in a beam of greater intensity; and this was the first step in what is called the dioptric* or refracting system.

It would be altogether out of place in this Journal to give a history and exposition of the catoptric and dioptric systems of lighthouse illumination. All that we aim at is to give our non-professional readers, in as simple phraseology as we can, a plain description of some of the apparatus most generally employed for the illumination of lighthouses; and if we succeed in doing this, we shall have attained our object.

The early reflectors used in lighthouse illumination, as described by Mr. W. Hutchinson of Liver-pool, in a volume on “Practical Seamanship,” published in 1791, consisted of small pieces or facets of common mirror-glass arranged in a hollow mould and fixed in their places by plaster of paris; but soon afterwards the facets of mirror-glass, though forming good instruments for their day and of their kind, were discarded, and the reflectors were made of copper plated with silver and brightly polished. The reflectors are carefully formed to the parabolic curve, and that curve was selected because all the rays, falling on the surface of a parabola from a luminous point placed exactly in its focus, are projected in directions parallel to its axıs, so that when the axis of the reflector is pointed towards the horizon a strong cylindric beam of light is thrown forwards in that direction. The reflector is illuminated by an argand burner, and its power as used for revolving lights has been estimated at about 450 times that of the unassisted flame. Were the light which is placed in the focus sufficiently small, and the form of the instrument perfect, the beam of light projected would be no larger than the diameter of the reflector, the largest of which is twenty-five inches, so that the space illuminated at the horizon would be a small disc of only that size, and the instrument would thus be useless as a light for the mariner, as it might never chance to come within his vision. But as the argand lamp-flame, instead of being a mathematical point, is of considerable size, the rays passing from the outer or en-focal portion of the flame are not sent parallel, but have a certain amount of divergence which, with a flame an inch in diameter placed in a reflector of four inches of focal distance, is equal to 14° 22′. This divergence or spreading of the rays causes the light to be visible over a considerable extent of the horizon, and enables us to arrange these instruments on a circular frame in such a way that the rays from the different reflectors, instead of shining in so many distinct beams, blend together and form by their union a continuous band of light of nearly uniform intensity all round the horizon. Such an arrangement forms what is called the fixed catoptric light; and if it be desired to produce a revolving light, all we have to do is to place one or more reflectors on a frame having four sides, and by causing this frame to revolve by clockwork, we shall have alternately the sides and the angles of the frame presented to the observer, who will see a bright flash of light as each side bearing the reflectors comes into view, succeeded by dark intervals.

Fig. 6 represents a section of the reflectors as used in the Northern Lighthouses, with the improvements introduced by Mr. Robert Stevenson; a is the fountain for the oil; b, the burner, and the reflected rays are shown by dotted lines.

In fig. 7, in which the reflector is not shown in section, the lamp is represented as lowered down from the reflector by means of a sliding apparatus for guiding it. The object of this arrangement is to allow the lamp to be removed while the reflector is being polished, and to insure its being returned to its exact position in the true focus.

The dioptric system of illumination originated with the late eminent Augustine Fresnel. Instead of the independent burners used in the foci of reflectors, he conceived the idea of using one large central flame 3 1/2 inches in diameter and 4 inches in height, and arranging round it 8 large plano-convex lenses measuring 3 feet 3 inches in height and 2 feet 6 inches in breadth, so as to refract the light from the great central lamp in the manner ex plained in fig. 5. These lenses, being fixed on a frame and made to revolve, produce the same effect as reflectors arranged in the manner we have de-scribed; for, as each face bearing a lens comes round to the eye of the observer, he sees a bright flash, which is succeeded by a period of eclipse or dark-ness. The lenses employed by Fresnel were on the construction suggested by Buffon, and improved by Condorcet, for burning-glasses in the year 1788 The advantages of that construction will be readily understood. If a lens of 3 feet 3 inches diameter were ground to a continuously spherical figure, it is obvious that it would attain a great thickness at the axis, and that the loss of light by absorption in its passage through the thick glass, as well as by what is called spherical aberration, would be very considerable. But the lens used in Lighthouses is formed so as to avoid these disadvantages.

Fig. 8 is an elevation and fig. 9 a section of this instrument, which is called the polyzonal* or annular* lens, because it consists of a central lens (a) surrounded by a series of separate zones or rings of glass held together with cement. This beautiful arrangement, it will be seen, admits of the thickness of glass being greatly reduced, because were the surface of the lens ground to a continuous curve, it would assume a form approximating to that represented by the dotted line. It also allows the surfaces of the zones, according as they recede from the axis of the lens, to be ground to the necessary curvature for correcting the spherical aberration. Fresnel’s lenses were made of crown-glass, and their illuminating effect when lighted by the large four-wick lamp has been estimated at about 3000 argand lamps, or about seven reflectors. Their divergence is less than that of the reflector, being only about 5° 9′. Fresnel limited the height of his lenses to 3 feet 3 inches, which subtends an angle of about 56° at the focus. Beyond that limit the lenticular action could not be advantageously pushed, owing to the obliquity of the incident rays on the surface of the lens; and in order to intercept that portion of the light from the great lamp which passed above the lenses, Fresnel used a combination of refractors and re-flectors; but as that part of Fresnel’s revolving-light apparatus is now superseded by Mr. Thomas Stevenson’s totally reflecting holophotal* prisms, we need not here explain its construction. Suffice it to say, that the holophotal prisms effect by means of one agent what formerly was done by two, and moreover they do this by what is called total or internal reflection within the glass, instead of reflection from metallic mirrors, which absorb one half of the whole rays incident on their surface, so that a great saving of light is effected. Total or internal reflection was only applied by Fresnel to the fixed portion of lighthouse apparatus. We feel, how-ever, that we owe an apology to some of our readers for using terms of which we do not give the precise meaning, but the popular nature of this article prevents us from explaining such terms as “spherical aberration ” or ” total reflection.” This could not be done without using dry diagrams and hard words, which we fear would not be pronounced to be “Good;” and therefore we must ask the reader to be contented with the explanation afforded by the engraving accompanying this notice (fig. 12,), which represents the interior of a light-room with a first-class bolophotal revolving apparatus. The central parts of the glass-work are the polyzonal lenses, and the upper and lower tiers are the panels of holophotal prisms. The case containing the machinery for driving the apparatus occupies the lower portion of the lightroom, and against the wall are the clock, signal pipes, and barometer. If further information be desired, we must refer the reader to the published treatises on the subject of Lighthouse Illumination.

But the large polyzonal lens is properly suited only to revolving lights; it was not until Fresnel extended his researches to the improvement of fixed lights that he completed his dioptric system of Lighthouse illumination. He conceived the possibility of forming a hoop of glass, having the same profile as a vertical section through the axis of a polyzonal lens. The action of such an instrument allows the rays from a lamp in its centre to spread freely in the horizontal plane, while it only refracts them vertically, and thus produces a powerful band of light of equal intensity all round the horizon. But much of the light would obviously pass above and below this hoop, and in order to intercept all such stray light, Fresnel designed for his fixed light a series of totally reflecting prisms to be ranged above and below, so formed as to intercept all the rays falling upon them, and to project them in a direction parallel to those issuing from the central belt. Fresnel did not however, from the difficulty of its construction on a large scale, apply this beautiful apparatus in its most perfect form to large or first-order lights, but restricted it to small har-bour lights. Instead of a hoop he used for large lights a polygon of narrow lenses, with a sufficient number of sides to enable the lenses, in consequence of their divergence, to give at the angle formed by the junction of two of them a light not materially inferior to what is produced by one of the sides; and instead of upper and lower prisms, he employed inclined metallic mirrors.

When Mr. Alan Stevenson was instructed by the Commissioners of Northern Lighthouses to convert the fixed catoptric light of the Isle of May into a dioptric light, he resolved to attempt the construction of a truly cylindric hoop for first-class lights, instead of a polygon; and after overcoming various difficulties the work was successfully accomplished by Messrs. Cookson of Newcastle, and put into execution for the first time at the Isle of May. He further proposed to make the sections of the great central hoop, which are called “cylindric re-fractors,” rhomboidal, so that the junction of the frames inclosing the glass-work being inclined from the perpendicular should not in any azimuth intercept the light throughout the whole height of the refracting belt; and lastly, he suggested the adoption (on a larger scale) of Fresnel’s totally reflecting prisms as a substitute for the inclined mirrors in the first-class lights; and in carrying out this latter suggestion, he has acknowledged the obligations he was under to M. Leonon Fresnel, the brother of the distinguished inventor of the dioptric system, for his kind assistance and co-operation.

All that was then required to perfect this bean-tiful apparatus was the introduction of inclined or diagonal framing, and a lantern with diagonal astragals (as shown in the engraving of the interior of the lightroom), so as to avoid the interception of light caused by the interposition of an upright bar between the light and the eye of the observer. Fig. 10 represents the first-class fixed light apparatus in its most improved form; and the reader can easily imagine that the rays proceeding from a lamp placed in the centre of this cage of glass, which is six feet in diameter and ten feet in height, are so refracted by the middle belt and reflected by the upper and lower prisms as to be gathered into one band of light of uniform intensity, which is spread over the surface of the sea, where alone it can be seen by the mariner.

The manufacture of dioptric apparatus was long confined to the French, who greatly excelled us in the purity of the glass and the machinery for grinding and polishing the surfaces; but Messrs. Chance of Birmingham have devoted a compartment of their extensive works to the manufacture of glass for lighthouse purposes, and, having adopted every conceivable mechanical arrangement for grinding and polishing prisms of any required form, they can now turn out the most complicated apparatus finished in a very high style of workmanship. The manufacture of lanterns and the whole framing and machinery necessary for a lighthouse has been brought to a very high degree of perfection by Mr. Milne of Edinburgh.

Such is a very brief outline of the catoptrie and dioptric systems of illumination; and to illustrate the different applications of optical engineering we may describe very shortly some arrangements of Mr. T. Stevenson to meet the requiremeuts of particular localities. One of these is what is called the condensing light. In fixed lights of the ordinary construction the rays are distributed, as we have just explained, all round the horizon; and such an apparatus, though well adapted for an island or rock surrounded by the ocean, is quite inapplicable in a narrow sound or arm of the sea, as shown in fig. 11. On the side next the shore no light is required; across the sound a comparatively feeble beam is all that is needed; while along the sound in the direction of a, b, and c, d, where the distances are greater, the light requires to be more powerful. If an ordinary fixed light were employed in such a situation, and made of sufficient power to light the channel in the directions a, b, and c, d, it is obvious that it would be much too strong for the shorter distance across the sound, while the light shining towards the land would be altogether thrown away. Such an arrangement would therefore occasion a great expenditure of oil for no purpose. By using the condensing apparatus the whole of the light pro ceeding from the flame is allocated or distributed in different directions in exact proportion to the distances to which it is wanted to extend, and the stray light, which would otherwise be wasted upon the land, is thrown or condensed in the directions in which the strongest light is required. This effect is produced by combining certain straight prisms and other optical agents with the ordinary lighting apparatus, and was first used in 1857 at three lights in the Sounds of Skye and Mull on the west of Scotland. A small burner was found to produce, in the only direction in which great power was required, a light equal to the largest class of apparatus; and the saving in oil, &c., on the three lights referred to, was estimated at from 400l. to 500l. per annum.

Another application of straight prisms called the “apparent light” has been found very useful in indicating the positions of tide-covered rocks lying near the shore. In this case the apparatus is placed on the top of a beacon erected on the rock, and is illuminated by a beam of parallel rays thrown from an apparatus on the land. The effect produced may be compared to that of a ship’s lantern placed on the top of the beacon, and it has been called apparent because the light appears to proceed from the beacon, whereas the light itself is on the neighbouring shore, and its reflection alone is visible. This apparatus has been for many years in use at Stornoway, where it has been found by seamen seeking shelter during the night to be quite successful.

The question of distinction still remains to be noticed. It is obvious that, if all lights had the same appearance, they might quite as well not be exhibited, as they would not enable the sailor to discover his position on the coast, and would thus lead to utter confusion; each light, whether catoptric or dioptric, must therefore have its own distinctive appearance, such as the sailor can readily distinguish and instantly recognise. The following are the distinctions most generally adopted, care being taken to arrange the order of the lights so that those having the same character may be as widely apart as possible. The fixed white exhibits, as its name implies, an uniform and steady appearance; and we obtain a fixed red by using lamp-glasses stained of a ruby colour. The revolving white is produced by the revolution of reflectors or lenses in the manner already described; and as the revolution exhibits a light gradually increasing to full strength, and in the same gradual manner decreasing to total darkness, its appearance is extremely well marked, so well, indeed, that when Inchkeith was changed from a fixed to a revolving light, a certain old lady, who had beguiled many a sleepless hour in watching it, was greatly puzzled by its successive appearance and eclipse, and declared in the morning that the poor light-keeper was much to be pitied, for ” no sooner was his lamp lighted than it went out, and if it had been lighted once, it had been lighted a hundred times!

The succession of red and white lights is caused by the revolution of a frame, whose alternate faces carry reflectors with chimneys of clear and ruby-coloured glass. And here we may mention that various colours have been tried, such, for example, as green and blue; but these colours are visible at distances so short as to render them unfit for sea-lights, the red alone being suitable as a marked distinction visible at great distances. The flashing light is produced in the same manner as the revolving light; but owing to a somewhat different arrangement of apparatus, and a faster motion of the revolving frame, a totally different and very striking effect is produced. The brightest and darkest periods being but momentary, this light is characterised by a rapid succession of bright flashes, from which it gets its name. The intermittent light is distinguished by bursting suddenly into view and continuing steady for a short time, after which it is suddenly eclipsed for half a minute by shades worked by machinery. The last two distinctions were first introduced into the Northern Lighthouses by Mr. Robert Stevenson. Double lights are sometimes exhibited from the same tower, one above the other, and sometimes from different towers, in which latter case, when kept in one line, they are generally designed either to indicate some navigable channel or to guide vessels past some danger.

Some lights which are near towns have been illuminated with gas, but its application cannot be extended to remote localities, and colza oil, obtained from the seed of a species of wild cabbage, is used in most of the lights in Britain. The argand lamp, with a standard flame one inch in diameter and two inches in height, consumes about 40 gallons; and the first-class lamps for dioptric lights, with a standard flame of 3 1/2 inches in diameter and four inches in height, burn about 800 gallons per annum. These large lamps have four concentric wicks, the outer or largest being 3 1/2 inches in diameter. The oil for their supply is forced up in a constant stream by small pumps worked by machinery. The supply is much greater than the consumption, and the overflow of oil through the wicks, which falls back into the cistern, prevents the soldering of the metal wick-holders from being melted by the great heat generated, and if the overflow ceases, the burner is at once destroyed. A small bell struck by the same machinery that pumps the oil indicates that the machine is continuing to do its duty; so soon as its constant tingle ceases, it is time for the light-keeper to start to his feet and look out for the safety of his lamp. The distance at which a light is visible depends on its elevation above the sea, and varies of course with the state of the atmosphere. We are not aware of any oil light having been seen at a greater distance than the holophotal light of Allepey, in Travancore, which is visible from the Ghaut Mountain, distant about 54 statute miles. Still, in our ever-changing climate, subject as it is to cloud and haze, there can be no doubt that any method of increasing the intensity of our lights should be hailed with pleasure both by the engineer and the sailor. We cannot get more light with our present apparatus, for if we increase the size of the flame, we lose by unnecessary divergence. What we want, therefore, is light of greater intensity; and it is that important quality which gives to the lime-ball light, and to Professor Faraday’s electric light, all their value for the purposes of illumination. The oxyhydrogen or lime-ball light has not as yet been found to work steadily or satisfactorily. The magneto-electric light has been adapted to lighthouse illumination by Professor Holmes, and was tried by the Trinity House of London, at the South Foreland in 1858, and latterly at Dungeness in 1862. A steam-engine forms a part of the apparatus required for producing the electric light, which would, doubtless, prove a barrier to its use in our rock stations, such as the Eddystone or Bell Rock; but the chief difficulty which has been experienced in bringing this light into practical use is its tendency to sudden extinction. The Elder Brethren of the Trinity House reported in Sept. 1862, “that with their present knowledge of the electric light they do not feel justified in sanctioning its exhibition from any lighthouse where provision is not made for its instant substitution by a light in ordinary use, it appearing to them that the contingencies to accident attaching to the electric light render such precaution absolutely necessary.” The same perseverance and skill that have brought the electric light to its present state may however perfect it as a practical source of illumination; and to ensure that desirable end, it cannot be in safer hands than the Trinity House of London, aided by the advice of Professor Faraday and Professor Holmes.

But, however intense the light may be, it is confessedly wholly unavailable to the mariner in certain states of the atmosphere. We have, by repeated observation and measurement, ascertained that it is no uncommon thing during fogs for objects in daylight to become invisible at the distance of from 200 to 210 feet; and at night for street-lamps to be obscured at distances of from 280 to 300 feet. On one occasion, indeed, we found that in daylight objects on a country road ceased to be visible at 60 feet. In such cases, when the sun in the firmament is obscured, even the electric light would fail to reach the mariner’s eye, and we believe that slow sailing and a free use of the sounding lead are the sailor’s best resources under such circumstances. During the erection of the Bell Rock Lighthouse, the landing boats had to make passages between the attending vessels and the Rock, and much inconvenience and danger occurred during foggy weather, as they sometimes missed the vessels altogether and were tossed about for a whole night. And when it is considered that in 1807 the aggregate time of low-water work-caught by snatches of an hour or two at a tide-did not amount to fourteen days of ten hours! and that in 1808 it fell short of four weeks, it will at once be seen how important it was to miss no opportunity of effecting a landing during spring tides. All devices were therefore tried in the shape of fog signals, for, during that state of the atmosphere, the sea is sometimes very calm; and Mr. Stevenson has stated as the results of these trials, that sound is much lost in foggy weather and is heard at a comparatively short distance, and that the “tremulous ” and sustained noise produced by a horn or bugle is preferable to a bell or even a gun. The shrill shriek of the steam or railway whistle, being now used in all steamers, is so common a sound at sea as to render it not suitable as a lighthouse fog signal; but at some of our lighthouses and harbours, large bells and gongs are tolled, and at others guns are discharged; and Mr. Daboll, an American, has introduced a trumpet sounded by a blast of air compressed by an engine or other power which is said to produce a wonderful effect: and we are glad to learn that it is about to be tried in this country by the Trinity House. The great drawback to all such signals is the difficulty during a fog of telling from what direction the sound proceeds, and of this we have known repeated instances. Sound may indicate the nearness of a danger, but it does not tell in what direction it lies. The subject, however, is highly important, and we hope that the papers of Dr. Gladstone, read before the Royal Institution, and of Mr. Cuningham, the secretary to the Commissioners of Northern Lighthouses, read before the Royal Scottish Society of Arts, may have the effect of directing further attention to it.

The management of our lights is entrusted to three Public Boards, viz., the Trinity House, for England and the Channel Isles; the Commissioners of Northern Lighthouses, for Scotland and the Isle three Boards, in so far as regards proposals for new lights and matters of expenditure and ac-counting, are subject to the control of the Board of Trade. Whatever diversity of opinion may exist as to the provisions of this Act, there can be no doubt that the enactment, which provides that in future the expenditure for new lighthouses should be defrayed out of the Consolidated Fund, has been of great benefit to the shipping interest. Previous to this the only funds applicable to the execution of new works were the surplus dues which remained unexpended after the ordinary maintenance of the lighthouses had been provided for; and while this necessarily imposed an extra burden on the shipping who paid the dues, it also delayed the erection of lighthouses in localities where they were much needed, and which were only postponed from want of money. But when the cost of new works came to be defrayed out of the Consolidated Fund, the same restriction no longer existed; and on the shores of Scotland alone no fewer than eighteen new lighthouses and fourteen new beacons have been erected at a cost of about 175,000l. since the passing of the Merchant Shipping Act, while the dues now levied, being only what are required for the ordinary maintenance of the lights, have been greatly reduced. The number of lights in the United Kingdom under the management of the three public boards and local authorities is now about 357, the light-ships 47, the beacons 261, and the buoys 1109.

Two light-keepers have the charge of each of the ordinary lighthouses, and at the Eddystone there were originally the same number; but one of the Eddystone light-keepers, having been taken suddenly ill, died, and his only survivor feared to commit the body to the sea lest he should be charged with murder in absence of all evidence of the man having died a natural death. He accordingly allowed his dead comrade to remain so long in the lighthouse that it became uninhabitable; and he was driven in despair to remain in the balcony till the attending boat could land at the rock and relieve him. To guard against the recurrence of so unhappy a casualty, all such inaccessible stations are now provided with four keepers, three of whom are constantly on the rock, while the fourth has his turn ashore with his family, and it is his duty to watch a daily signal made by hoisting a ball in token that all is well. If the ball be not raised, it is his duty to proceed to the lighthouse in the attending boat with all convenient speed. But at such places as the Bell Rock it is sometimes impossible to land for weeks together, and previous to the employment of steam, a period of nearly three months has been known to elapse before the change of light-keepers could be effected. The process of landing amid surf and breakers on tide-covered reefs or rock-bound coasts, and again boarding the tender in a heavy sea-way, is not the most agreeable duty connected with the service; and it is not with feelings of pleasure that we look back on some of our ” difficult landings” on the northern shores of Shetland, the western coast of the Hebrides, or the Pentland Firth.

From what has been said as to the importance of strict regularity in the exhibition of lights, we think our readers will fully appreciate the vast importance of securing trustworthy and capable men to perform the highly responsible duties of light-keepers, and from pretty long experience, we are enabled to state that the greater number of men so employed in the northern lighthouses have been of a superior class, fully alive to the importance of their duties, and some of them occupying much of their leisure time in the improvement of their mind. The regulations imposed on light-keepers are very stringent, but not more so than the responsible nature of the duties demands, and, coupled with periodic inspections by members of the Board and their officers, to see that these regulations are faithfully observed, a discipline somewhat akin to that of the military or the naval service is maintained. As an illustration of this, we may mention the signal tubes which communicate from the lightroom to the bedrooms of the dwelling-houses, and no man, on pain of dismissal from the service, is permitted to leave the lightroom on any pretence whatever without in the first place summoning his colleague to supply his place. A constant watch is thus kept up so long as the lamps are burning; and in a long Shetland winter night, extending from three in the afternoon till nine in the morning, the four hours’ watches, which are taken by rotation, come to be a pretty heavy part of the duty. Seated in the isolated lightroom, far from the bustle and din of town life, the light-keeper spends many an hour of absolute seclusion, but, strange as it may seem, even he is not altogether exempt from the annoyance of nocturnal visitors. Whole flocks of small birds, driven by the wind from the coast and attracted by the dazzling light, have sometimes, like a living shower, been driven against the lantern and de-stroyed; and even large sea-birds, hurried onward by the gale, have occasionally struck the thick plate-glass, and shivering it to pieces, fallen dead on the lightroom floor, while the lamps have been wholly or partially extinguished. The keeper then sounds his alarm, and applying a storm pane (which is always in readiness in case of accident) to the breach made by the misguided gull, his lamps are speedily relighted. It is not often, however, that the midnight reveries of the light-keeper are so interrupted, and night after night, amid the roar of waves and the howl of tempest, he holds his watch in solitude. A circulating library (in the truest sense of the word) has in some cases been sent round the coast from station to station, each box containing a stock of well-selected books, which, after a reasonable sojourn, are packed up and forwarded to the next lighthouse.

It must not, however, be supposed that the light-keeper’s time is not fully occupied. In summer, where the soil admits of it, he has a garden to till, and in winter, when the night-watches are pro-tracted, the ordinary duties of the lightroom, if faithfully discharged, occupy a large portion of the short day. A careful statement must be made of the oil and other stores nightly expended; a record must be kept of the barometer, thermometer, rain-gauge, and direction of the wind; and a journal given of the number of vessels seen to pass the lighthouse, and anything that may happen worthy of notice at the station.

Proposals have been made to extend telegraphic wires to some of the outlying lighthouses, so that outward and inward bound vessels might signal on passing the lighthouse, and the keepers might telegraph these messages for the benefit of their owners or insurers. But in reply to this suggestion we have always maintained that the light-keeper’s first duty is to secure the efficient and regular exhibition of the light under his charge, and that no encouragement should be given to impose upon him any occupation that might interfere with his legitimate duty, more especially if the extent of such occupation could not be defined, and the time of its execution from day to day restricted to certain hours. It has also been suggested that lighthouses might be made available as lifeboat stations; but the same difficulty applies with even greater force to such a proposition, because, if the light-keepers were, in case of shipwreck, to render any personal service at all, it would necessarily take them away from the lighthouse in states of the weather when it is all-important that the light-room duties should be performed with, if possible, more than ordinary assiduity, when the outside of the lantern windows has perhaps to be cleared several times in the course of the night of snow-drift, and the inside of condensed water caused by extreme cold. But, indeed, as lifeboats can only be used in the neighbourhood of towns or villages where the population affords a sufficient number of horses and men to launch them, and a sufficient crew of willing and experienced seamen to man them, we have never been able to see how our lighthouse stations can in any way be made available for such a purpose.

To the remote and isolated sites of many of our Northern lighthouses the easiest and, in many cases, the only communication is by sea, and the various stores required for maintaining them are conveyed to the Northern Lighthouse Stations by the Commissioners’ steam-tender “Pharos,” an arrangement which is to some extent adopted in England and Ireland; but the geographical formation of the country renders the English and Irish lights less dependent on water communication than those of Scotland, with her far-stretching Highlands and numerous outlying islands. In many parts of Scot-land, indeed, the light-keepers have no opportunity of attending church, or their families a school; and this evil is, as far as practicable, lessened by making periodical changes in the appointments to these remote stations. The Commissioners of Northern Lighthouses are consequently in many cases obliged to make provision for medical attendance, and they have, with laudable consideration for the interests of their servants, a missionary as one of their regular officers, whose duty it is to pay visits to certain remote stations, remaining from one to four weeks, according to the necessities of the case and the number of young people to receive his instruc-tions. There are fifteen of the Northern Lighthouse Stations regularly visited by Mr. Easton, the missionary to the Board; and the isolated character of these places, and the necessity which exists for providing for the spiritual wants of their secluded in-habitants, are borne out by the following tabular statement of stations visited by the missionary, from which it will be seen that in some cases they are upwards of twenty miles removed from church or school.

At most of these stations, therefore, the families are almost wholly excluded from the privilege of attending church, and on one occasion a light-keeper took his child a journey of thirty-five miles to be baptised! The missionary now baptises most of the children, but he has never dispensed the Sacrament of the Lord’s Supper, and if he were enabled to do so, it is believed it would greatly enhance the value of his ministrations among his widely scattered and secluded flock.