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the whole light into a few sheafs of on the Start Point, with one of these lenrays, which could be easily made to ticular arrangements. Since that time, revolve, while the light which radiated this apparatus, variously modified, has above these lenses, was sent along the been gradually replacing the silvered surface of the sea by a combination of reflectors in our British lighthouses ; lenses and mirrors. This apparatus was but only gradually-for the Board of proposed by its inventor for the Tour de Trade lay it down as a principle, that Corduan ; an experiment was made with the expense involved by the change it, on the 20th August, 1822, before the should only be incurred when the reCommission des Phares; it was considered flectors are worn out, and they will often successful, and the plan was adopted. last, when handled by careful keepers, But the French government did not for forty years. The governments stop here. A comprehensive scheme was of the United States and Spain have, proposed for improving the lighthouse within these last few years, instituted system of the country, building new a complete reformation in the lighthouse lighthouses, altering old ones, intro service of those countries, and have ducing the lenticular apparatus, and adopted the lenticularsystem throughout. varying the appearance of the lights. The lenses first used in England And badly enough was such a general were manufactured, we believe, at Newscheme wanted. The French coasts were castle
e; but they were poor affairs, then wretchedly lighted; for instance, and subsequently the contracts were there appears to have been only one given to French houses.
But English Frenchlight in the Mediterranean. manufacturing ingenuity was not to be Sixteen others were proposed. The baffled ; and now the Messrs. Chance, of French side of the Channel was better ' Birmingham, make apparatus equal
, if supplied ; yet even there great changes not superior, to all others. A visit to were loudly called for. The matter was their works is most interesting; and it entrusted to M. de Rossel, whose gene would be instructive to describe the ral scheme was approved by the Com mysteries of the melting-pot, and the mission des Phares, May 20, 1825, and advantages of cross-stroke grinding; but referred to him and Fresnel for further space does not permit, and perhaps the development; which was given to it in a reader is thankful that it does not. report dated September 9th of the same Attempts have lately been made to year. This comprehensive plan was employ pressed instead of ground glass. speedily carried into effect, and the The chief advantage is economy; but it lighting of the coasts of France became is an economy we do not care to pracalmost as good as it is at the present tise even in our household glass, much day.
less in optical instruments. There is a The merits of the lenticular arrange little pile lighthouse near Calais, standment did not long remain unappreciated ing in the water on its long iron legs, by other countries. The Dutch have the which is fitted up on this plan ; but, credit of first following the good ex though immense ingenuity has been example. The Scotch Board soon sent pended on it, the experiment cannot be their engineer to study the new system; deemed satisfactory. It was at Lonbut, though constantly urged on by Sir donderry that a lens of pressed glass David Brewster, who had long pre first came under my notice, but the viously experimented on lenses, it was man in charge did not know which way only on October 1st, 1835, that the to place the convex side ; and in a tower first lens-light was exhibited in Great on Lough Foyle a similar lens was Britain, at Inchkeith, in the Firth of actually turned the wrong way. Forth. This was quickly followed by In the centre of this system of lenses a change in several other Scotch lights, should be the most powerful flame that and by the Trinity House, in 1836, can be produced. Four concentric wicks, furnishing a newly erected lighthouse, each capable of moving independently
of the other, with a mechanical arrange The rays passing above or below the ment for pumping up the oil, were em band of lenses are caught and sent into ployed by Fresnel ; and the regulation the desired direction, not by mirrors, quantity of colza oil annually consumed but by totally refracting prisms of glass. is 785 gallons for each first-order lamp The first apparatus of this character in France. Now it must be remembered, erected was at the Pedra Branca rock, that the amount of oil burnt is pretty near Singapore, in 1850 ; but the prinnearly a measure of the light produced; ciple has been extensively adopted since. and, as all other expenses in a lighthouse A fixed apparatus of this character is remain the same whether the flame be like a gigantic bee-hive, the encircling great or small, it is evidently the worst bands of which are made of glass; and, economy to stint the oil. Yet this has if for a first-class light, it is capacious actually been done systematically in enough for several persons to get inside England and Ireland, where, partly from it at once, and walk round the central inferiority of lamps, partly from the fire, and view the image of the landrejection of the fourth wick, and partly scape in each separate piece of glass. from not encouraging the keepers to If it is desired not to illuminate the burn a high flame, the quantity of oil whole circle, and to send a particularly consumed is not much more than half bright beam in one or two directions, what it ought to be-averaging, respec as frequently happens in the narrow tively, 474 and 442 gallons in 1857. channels among the Western Isles of And this error tells more fatally, since Scatland, the rays passing towards the it is only the light from perhaps two undesired quarter are caught by lenses inches or more above the burner that and a row of vertical prisms, and sent ever finds its way to the sea through the exactly to the spot where their brilliancy lenses so that, as the Royal Commis- does good service to the sailor, winding sioners actually found in their visits, his way through those tortuous seas. when low flames were employed, little An effective combination of the beyond the yellow points of the flame metallic reflector and the lens is in were serviceable to the mariner.
some places adopted, where the rays in Oil lamp with both lenses and reflec front are parallized by the transparent tors. Even in Fresnel's original design glass, and the rest by the parabolic it was proposed to catch and to utilize metal, with the exception of those at the light which passed above the lenses the back of the flame, which are reby reflectors of looking glass; and turned through it by a spherical mirror, several existing lighthouses contain and sent through the lens. apparatus on this principle. But the It is self-evident that the proper adcombination of the two systems has justment of these different pieces of drawn forth the ingenuity and talent of apparatus is a matter of the utmost the family of the Stevensons. The two importance ; for it might easily happen systems are called, respectively, the that they should send the light up to catoptric and the dioptric, from the the stars, or down to the shore. The common optical terms ; but in this paper Royal Commissioners suspected that in these terms have been hitherto avoided, many cases it was so; and the bright and it is not my intention to trouble the idea occurred to their Secretary, Mr. reader with the distinction between J. F. Campbell, that it would be easy catadioptric and diacatoptric, or to de to determine where the light of the scribe in detail an “azimuthal condens- lamp fell on external objects, through a ing catadioptric holophotal apparatus.” particular piece of glass, by observing It would not indeed be possible to do so what external object was visible through without diagrams. The three following that piece to an eye placed where the points may suffice to show the important flame should be. By this method of modifications which Mr. Thomas Steven internal observation the sadly defecson has made of Fresnel's idea.
tive state of many of our lighthouses
was proved to demonstration. The intermittent, made by bringing a screen Astronomer Royal took a strong view before the flame ; and there are double of the case, saying of one instance: “It lights—for instance, the double revolving “really gave me a feeling of melancholy light at the Calf of Man, the ludicrously “to see the results of such exquisite characteristic effect of which I well “ workmanship entirely annihilated by remember, as it seemed to wink at our “subsequent faults in the mounting and passing boat, first with one and then "adjustment." The attention of the with the other of its fiery eyes. On Trinity Brethren was called to this the night after that fearful day when defect; and, by the zealous co-operation the Royal Charter was wrecked, I stood of Professor Faraday and Mr. James on the pier at Honfleur ; and, while the Chance, means were devised for re vessels were tossing about, the desirableadjusting the bands of glass, or for fixing ness of good distinctions was deeply them properly in the first instance. impressed on my mind—for there, at the During this investigation several mouth of the Seine, were eleven difcurious facts were noticed. Thus sailors ferent lights, most of them having just at Whitby had complained that the the same appearance; but among them lighthouse gallery cut off the lower stood conspicuous and unmistakeable the beams of light; it was not the gallery, light of Fatouville, alternately steady but the very prisms of glass which ought white, dull red, red flash, dull red, to have gathered up that light for the steady white. There is something benefit of the sailor. The revolving light peculiarly impressive in the constant at Cape Gris Nez has been praised both change of white, white, red, at regular in parliament and out of it, and has intervals, in such a lonely situation as drawn upon itself the special admira the Tuskar or Cape Wrath, when seen tion, not only of those landsmen who on a dark night from the deck of a ship may run across by night from Folke- sailing on to the wide Atlantic. stone to Boulogne, but also of the New sources of light. Why should seamen who frequent the whole of the we be confined to the combustion of British and French waters. Yet the oil ? The Pharos of the future will French authorities thought rather perhaps be as independent of it as is meanly of the light at Gris Nez:-it our present street lamp. was an old-fashioned thing, one of the Coal gas. Though the use of gas
has first dioptrics put up, without any of been frequently pressed upon the attenthe modern improvements. The com tion of the great lighthouse authorities, mission visited Gris Nez; and, true they have never adopted it, conceiving enough the apparatus was old fashioned. it to be dangerous. The municipal But it was accurately adjusted-probably bodies, however, have not participated by Fresnel himself; at any rate by some in this dread, and a large proportion of one who was not content with ordering even the most important harbour lights a beautiful, complicated, and costly piece owe their illumination to this source. of mechanism, and getting a mason to Some of these are admirably managed set it on top of a tower.
and most efficient; but there are others It is not in the above respects alone which present a sad contrast—as that at that great ingenuity has been displayed Dover, of which it is reported : “The in lighthouse apparatus. In order to green light was only distinguishable distinguish one light from another, some as the dullest of lights round the are made to revolve, while others remain “barbour, and by a greenish or blueish stationary. The rates of revolution also hue, not very discernible.” vary. Again, while the majority are The same optical apparatus is appliwhite, many are red, and a few
and cable to a gas as to an oil-flame. some revolving lights are alternately Electric light. All other lights that white and red. There are also other science has produced appear dim beside varieties. There is a bad variety called the the splendour of that small spark which
bursts into view when the conducting was continued for some months, and wires of a powerful electric current are was considered successful. But the separated by a minute space, especially light was afterwards removed from if these wires terminate in charcoal the South Foreland, the dioptric appoints. The worst is, that it is difficult paratus of which was ill-adapted for to maintain this spark in a constant it. Some improvements have since been state of brilliancy. Many attempts made ; and it is now fitted up with have been made to overcome this diffi- optical apparatus of its own, at Dunculty, and many proposals have been geness, and will, probably, be shining submitted for introducing electric lights again before this paper is printed. It into lighthouses; but the only one is intended that it shall be permanent. which has been so introduced is that Professor Faraday, who first discovered of Professor Holmes. In 1853 he was magneto-electricity, and who is the called to examine some magneto-electric scientific adviser of the Trinity House, machines that were intended for the has naturally taken a great interest in decomposition of water, and it occurred the development of this child of his, to him that they might be made available and in seeing it take a part in the for producing the charcoal light. He active business of the world. got the light, and set to work to perfect Lime light. Captain Drummond atthe apparatus. In February, 1857, he tempted to introduce into lighthouses first communicated with the Trinity the brilliant light produced by the House ; and, on December 8, 1858, incandescence of a piece of lime in an this brilliant star first beamed forth oxy-hydrogen flame; but, at that time, over the seas from a lighthouse—that the difficulty from the cracking of the at the South Foreland-surprising the lime could not be sufficiently overcome. sailors, and the inhabitants on the Mechanical genius, however, has done opposite coast of France. The light, much to remove this, and for three as in other cases, is derived from com months during the past autumn a light bustion ; but it is the combustion of of this character was exhibited, as an coal in a small steam engine, which experiment, at the South Foreland. rotates a wheel loaded with soft iron Should either this light or that from cores past another wheel loaded with the magneto-electric machine eventually permanent magnets. This calls into come into general use, England will action a force which, carried aloft by have the honour of initiating an imstout wires and allowed to pass between provement in lighthouse illumination the charcoal points of an ingeniously- equal, if not superior, to that effected in constructed “lamp,” produces a light France by the genius of Fresnel. Long which can only be compared to a may there be such a rivalry between the fragment of the sun. The experiment two nations !
THE CURSE OF ROME.
BY RICHARD GARNETT.
[Written after reading Count Montalembert's letter to Cavour, in which
he contends that the temporal power of the Pope should be maintained for the benefit of “the Catholic world.”]
IN France throned Despotism's foe and fear,
To quell the aspiring spirit else unbent,
As a Brazilian traveller lulled and bled
Of pictures ; Venice shipless ; where erst flew
And grow! But, as an arid water-course
Romeward ascending. Who art thou would'st go
What! Rome must wither 'neath the oppressor's hand,
Of Paradise ? Can earthly changes mock