wasteful. M. Jamin has recently taken power produce 600 candles; the Trinity a step in advance in this line, and the House, 1,254; a Paris commission, 2,500; trial of his lamp is being eagerly a certain Anglo-American Light Comwatched. pany, an unknown quantity!

We have not yet obtained perfection in the arc lamp. We want brilliance, combined with absolute steadiness, and the durability of a winter's night. Great steps have, however, been made in simplification of parts and smoothness of action; but we lack silence and steadi

ness.

We have two natural standards to refer to, sunlight and moonlight. We have various physical forces to appeal to for measurement, photographic records, the production of heat, the estimation of shadows, &c., but the standard of the future remains an ignis fatuus. To estimate the value of a light, you must not look at it; you must turn your back to it; you must try and read small print by it, and then you will find what a godsend it would be to find some means by which we could estimate the illumination of a square foot or a square yard. We want not only a new standard of light, but we want a new system of photometry. Efforts have been made to estimate the intensity of the light radiated by the size of the craters found on the carbon rods; but this mode of measurement is empirical and illusory, for it varies with the character of the carbons and the currents used.

Many of the defects of the arc light are compensated for in that of incandescence. Here we have something that is beautifully soft, absolutely noiseless, perfectly steady, a light that brightens up nature in all her true colors and purity. I shall not readily forget a dinner party given by Mr. Spottiswoode, the President of the Royal Society, a short time ago, when his room was illuminated by Mr. Swan's lamps. It was not only fascinating, but fairylike and lovely. One felt in a dream. We have had a sample of it here, and the beauty of the light grows on you. The incandescent light is, however, at present, an A word about that "philosopher's expensive luxury. It requires a consida- stone," that elixir vitæ, the subdivision ble expenditure of power. For instance, of the electric light. What does it Sir W. Armstrong finds that six-horse mean? It means that certain gentlemen power supplies 37 lights, giving alto- hope, from one central spot, to distribute gether 925 candles. Six-horse power in electricity, as they do gas and water, arc lights would give over six thousand throughout our houses, so as to furnish candles. However, we must not grum- great cities with cheap, pure and abundble. Rapid progress is being made in ant light. "'Tis a consummation dethis field. Maxim, Edison, &c., in voutly to be wished." Now, I am one of America; Swan, Lane.Fox and others, those who do not believe in the word in England, are working hard, while "impossible," but I say, that with our Gordon and Joel are working in an inter- present knowledge, this problem is inmediate field, where a prospect appears soluble. There are those who don't say of a happy compromise being effected between the arc and incandescence. We have, to-night, an illustration of the burning of the Joel lamp-a modification of that introduced by Mr. Werder

mann.

so, but who think I am an obstructive lunatic. But what are the facts? Numbers, thoughts, words, can be manipulated anyhow-hence Whig and Tory, High Church and Low Church, et hoc genus omne, but facts are inexorable. A good many wild statements are Sir William Armstrong can only keep 37 made about the light-giving power of lights going; Lane Fox could only show these different lamps. A standard sperm 12 lights; Professor Adams could only candle may be a very good unit to meas- produce from the most powerful dynamoure gas by, but it is a very poor stand- machine, by calculation, 140 lamps. ard for the electric light. Of course Where is the subdivision? The advothe advocates of the electric light over-cates of subdivision assume an exhaustiestimate their case. It would not be ble source of electricity. Their oppohuman nature if they did not; but their nents reply that there is but a very limidivergences are wonderful. Thus, the ted source of energy in every dynamoGlasgow committee makes one horse- machine. Subdivision means loss of

power, waste of energy, and useless ex- system would alone meet the case of penditure. We are not all Sir William such a place as the Waterloo railway Armstrongs, who can say of his brook, station. For the former we want height "I can afford to waste that which costs and space; for the latter length and lowme nothing." One ardent disciple of ness. In fact, the longer and lower the subdivision says: "There is practically place to be illuminated, the less is the no loss in dividing the electric light pro- intensity of the light required; and duced by this means (by incandes- when we come to long rooms and passcence)." Now, is the production of 925 ages, we possess all we require in the candles when you ought to have 6,000, small incandescent lamps. It is not no loss? Is the production of 3,600 difficult to show that such conditions candles on the Thames embankment, may arise, even in external illumination, where you ought to have 25,000, no loss? that a few small lamps, well distributed, Our dynamo-machines have their limit, will illuminate better than one or two and no power on earth, either of subdi- powerful ones. vision or of multiplication, can make the An eventful feature in practical lightmachine do more than a given amount of ing is the proper scattering or diffusion work. It may be that in course of time, of light, by shades, screens, and reflectand, probably, very soon, too, more pow- ing surfaces. There is an archway at erful machines and lamps of lower re Waterloo station that is wonderfully sistance, may enable us to light up a lighted, owing to the white glazed tiles greater number on one circuit, but this on its sides, forming such admirably is not subdivision, it is multiplication. I reflecting surfaces. We want to emulate anticipate more advantages from the the diffusion of daylight. It is marveltransmission of power, and I look for- ous how whitewashed surfaces do this. ward to the day when I shall have in my Well selected globes act as though they own house a small and simple dynamo- were self-luminous - they scatter light machine, working my own lamps, and no and prevent shadows. one else's. I have not the slightest ambition to be dependent on electric currents generated miles away, and liable to all the interruptions to which I, as a telegraph engineer, have had long and painful experience.

The reason why daylight is so diffused, and the light searches out the inmost corner of our cupboards and our drawers, is simply that practically the whole sky becomes the source of illumination, light radiating from each point. One interesting question that will be solved by the great experiment commencing tomorrow in the city, will be the relative efficiency of different lights in penetrating fogs. It is a point open to the observation of every one of us, that the electric light upon the Thames embankment exhibits no more power in penetrating fogs than gaslight. The reason of this is extremely simple. Light, as I have previously explained, is due to the undulation of matter. There are waves and waves; some like the mighty ocean swell, tossing the "Great Eastern" like a cork in a basin; others are reflected from the side of the cork, as the billows of a storm are tossed back by a solid pier. The color of the sky is due to the reflection of the tiny blue waves, by excessively minute material particles floating The same arguments apply for internal about. The red sky at night is due to illumination. Nothing can be more per- the unimpeded transmission of the fect than the centralized system at the larger red waves, the smaller ones being British Museum, while the distributed checked; hence the dull red of the

Now, having got our light, the next question is, how can we utilize it? This question, as far as external illumination is concerned, is about to be solved for us in a very interesting way by the city authorities. We have, first, the centralized system of Dr. Siemens, where one machine works one powerful light, raised like a small moon upon the top of a high mast; and we have, secondly, the distributed system of the Brush Company, who utilize the existing street lamp posts, one machine working many lights. I have no doubt myself, from my own observations, that for symmetrical spaces, large areas, such as docks, parades, squares, &c., the former is the best; but for long and narrow streets and thoroughfares, the latter will prove superior.

round sun in a mist, and the destruction ing sixteen lights. These machines will of the smaller rays of the electric light, be arranged to work together or separwhich lend it that bright and brilliant ately. There will be lamps in the violet tint in clear weather. For the citadel, in the engine and boiler-rooms, same reason that the penetration of the in the steering platform, below the torelectric light is no greater than gas, its pedo department, in the magazine and illuminating power in its immediate shell-rooms; they will be used for buoy neighborhood is more. For these small lights and mastheadlights, and probrays which had been checked by material ably, as there will be plenty of accomparticles from penetration are reflected modation on board for the production of back to the immediate neighborhood of electricity, the cabins will be lighted the light. There is a great difference with some incandescent lamps. The between the quantity and the intensity "Minotaur," again, is fitted with sixteen of light. There may be a light of very Brush lamps; and, in fact, for torpedo low intensity, but yet of such large purposes, the light is not only useful, quantity as to penetrate to a consider but absolutely essential. Last year I' able distance. A ship on fire at sea, for had the pleasure of spending some time instance, is seen to an enormous dis- in the Mediterranean on board a ship tance; and it must not be forgotten that laying a submarine cable between Marthe law of squares, by which the relative seilles and Algiers. Our operations intensity of light is determined, is true were carried on by night as comfortably only for points; it is not true for as by day, by the aid of the electric surfaces. A large flame of gas, though light. its intensity is so much less, may be as luminant as a point of electric light. field. Reading by gaslight is irksome; Beacon fires, though of very low in- reading by the electric light is simply tensity, are visible very far. In fact, if delightful. The Picton Gallery at Liverwe increase the luminous area as we pool has been so lit for a long time, and recede from it in proper ratio, we shall the British Museum is now permanently maintain the same amount of illumina- illuminated by five arc lights, which fully tion; hence the great failure of photo- answer the purpose. This has enabled metric measurements to which I have the authorities to keep the reading room alluded. A photometer measures the open daily through the winter till seven intensity of light, not its quantity. o'clock, and only on one day (and that It is important to acquire some experi- within a short time of the hour of closing) ence from the actual users of the electric have the lamps failed, the failure being light, and to know what amount of due to a want of proper fuel for the business has already been done. For engines. At South Kensington 32 Brush instance, there are nearly 300 Gramme lights are used with great success, and machines in use in England generating afford every satisfaction, not only as a light. There are many more Siemens', while the Brush people have already installed many machines and lights.

Libraries, again, have become a useful

luminant, but in an economical sense.

Railway stations are gradually adopting the lights. The Liverpool-street The Trinity-house, who have applied Station of the Great Eastern, the Padthe electric light to lighthouse purposes, dington Station of the Great Western, have at present confined its use to the Waterloo-bridge Station of the LonSouter Point, South Foreland, and the don and South Western, the CharingLizard. They find that the expense cross Station of the South Eastern, the involved in the installation of the light Bricklayer's Arms (Goods) Station of the is very considerable, and it cannot be South Eastern, are being practically and adopted without very strong and power- effectively lit, and the St. Enoch's and ful reasons. Perhaps the greatest ex- Queen-street Stations at Glasgow, as tension in the use of the light has been well as the Victoria Station at Manfor naval purposes. Nearly all our chester, are equally successfully being present ironclads are supplied with the lit.

electric light. The last addition to this Again, we find seaside resorts availing list, the "Inflexible," will have no less themselves of it for the illumination of than two Brush machines, each produc- their parades. Blackpool, for instance,

success.

has, with great enterprise, lit up the sunless winter without its aid. Whether whole of its parade and piers with great the exposure is for one hour in the sun, or three hours in the electric light, is a The new Albert Docks on the Thames, matter of no consequence, if the quality the Alexandra Dock at Newport, the of the results are similar; the sun, howMersey Docks at Liverpool, are all ever, has an advantage, due, doubtless, spreading the use of this light with con- to the greater quantity of light that it siderable speed. I was surprised last emits. year to find the Belle Vue Gardens at Perhaps, however, the most interestManchester (a pleasure resort that re- ing appliance from a scientific rather minded me very much of the old Surrey than a commercial point of view, is the Gardens we used to have in London) application, by our worthy chairman, of where, without any expert assistance, the this light to horticultural purposes. He active managers, the Brothers Jennison, has found that it fulfills all the requirehad rigged up several lights themselves, ments for the growth of plants and and had experienced neither trouble nor difficulty in the matter.

ripening of fruits; and he has at his country seat, near Tunbridge Wells, carried on a very large series of experiments, that have created quite a sensation in the scientific world.

It would be impossible to make any summary of the numerous works, mills, dye works, &c., that have been supplied with lights worked successfully. The Notwithstanding these great advances Iron works at Barrow, for instance, have in its use, it must not be forgotten that very extensively employed it; while the the electric light has its defects and its disTimes office was probably the first place advantages. All is not gold that glitters. in London to inaugurate the introduc- The intense shadows that it emits are tion of the electric light for such pur- troublesome. The unsteadiness of the poses. Shops and warehouses in all light is at times wearisome. The hissing parts of the country are now being lit that impurities in the carbon and irregup-Whiteley's, Shoolbred's, Nicholl's, ularities in the current produce is tantalRegent street, Crocker's warehouses in izing, and the light has an unfortunate Friday street, and many other places, habit of misbehaving itself when it is and now we find the city inaugurating most wanted. Moreover, the problem the illumination of their streets and of durability remains yet to be solved. open spaces. I never pass that wretched Many have tried it and abandoned it. In excrescence that indicates the site of old some cases its economy is unquestionTemple Bar, without wishing that the able; but there are places where careful heraldic beast that surmounts it were persons have shown that gas, as regards removed, and supplanted by a handsome economy, surpasses it. It is questionbronze pillar 30 or 40 feet high carrying able whether, in some cases, the electric a miniature sun. It would not only light does not affect the eye. The exmake the memorial more ornamental, perience, however, of the readers of the but it would make it useful as well. British Museum, is entirely in its favor.

One of the most useful purposes to Nevertheless, I have myself suffered which the light has been applied, is that much from the light; true it was in of photography. Not only are pictures experimentation, and the same thing taken by its aid in the wretched fogs of might have happened with any intense winter, that quite destroy the actinic light; but rumors do exist that eyes power of sun rays, but it is used to a have been affected, and probably suffivery large extent in carrying out what is cient time has not yet elapsed to solve known as the Woodbury process. The this question. The arc light produces, electric light is not so powerful as sun- also, nitrous acid and other deleterious light, i. e., it does not operate with the gases, as is shown in the condition of same rapidity. Electric light takes, in the lamps. The incandescent lamp, is, fact, three times as long to print gelatine however, free from this trouble. The reliefs for the Woodbury process, as the powerful currents that it requires cannot sun; but Messrs. Lock & Whitfield be carried over buildings and rooms assure me that they hardly know what without incurring danger from fire and they should have done during the past to life. It has been proposed to utilize

the electric light in coal mines, but, to my mind, one might as well lay a train of gunpowder along a mine gallery, if it be at all a dangerous one, as a wire conveying such powerful currents of electricity as a light needs, unless that wire be most carefully protected.

all the necessity for this ventilation. It does not vitiate the air. We have found at Glasgow, where we have applied the electric light, that all these causes of trouble have ceased. Health has been engendered, more work has been got out of men, and, in point of fact, the The disturbance due to induction I experience of others shows that the elechave already alluded to. Nevertheless, tric light will pay for itself even in the in spite of all these defects, the light has increased work that can be obtained out great and manifold advantages. The of labor in consequence of its use. Not brilliancy of a well-lit room is simply only is the health of the subject imenchanting. The purity of the light for proved, but men are able to do more the transaction of business, the selection work in a given time from the influence of colors, and the ordinary daily avoca- of this pure light than from the impure tions of life, is simply superb. The light of gas. We still want brilliancy cleanliness of the light is one of its great combined with steadiness and durability. merits. It emits no smoke; but probe- The advances made have not been so bly its greatest advantage is to be found much in this direction, as in the improvein the influence it exerts on health. We ment of details, and in a greater knowlall know that the air is vitiated to a cer- edge of electrical measurements and of tain extent, by the mixture of carbonic the relations that exist between elecacid with it, and it has been well shown that to be consistent with health there should be not more than six volumes of carbonic acid in ten thousand volumes of When the proportion reaches ten volumes to ten thousand, the action of the heart is affected. When this proportion runs up to from fifteen to thirty volumes in ten thousand, headaches occur, and in higher proportions, rheumatism and bronchitis are the consequences. Now, five thousand cubic feet of fresh air per hour per gas burner, consuming three feet per hour, are required to maintain your health; in fact, in our great galleries at the General Post-office, we if he had lived in the present day, he require two to three million feet of fresh would have considerably added to the air per hour to provide a healthy atmos- period in which he estimated the electric phere. The electric light sweeps away light to be an ornament.

tricity, heat, and light. Electricity as a
substitute for gas is not a delusion; it is
practicable. It supplies a real want;
but for domestic purposes it is at present
a luxury, and an expensive one. Predic-
tions as to its grand future have not yet
been fulfilled. The public have shown
themselves remarkably sensitive to its
influence on gas. Nevertheless, it has a
bright future before it, and, though the
poet might have said:

"It was a phantom of delight,
When first it beamed upon my sight;
A lovely apparition sent

To be a moment's ornament."

ILLUSORY SANITATION.

From "The Building News."

SINCE the institution of local and other with popular as well as legal authority, Boards charged with the duty of pro- we lost our individuality, and while contecting us from the dangers consequent tributing to the costs of such machinery on an improved system of sewerage, ills became mere helpless units in the force before unthought of have unpleasantly developed themselves, creating dismay instead of hoped-for comfort and contentment. In the gradual and unavoidable transfer of our personal control of the evils of the house to those endowed

by which it is impelled and governed. Ever since drains and their controlment budded into a science, many a theorist has had ample opportunity of airing his opinions, but in the course of the numerous tentative blunderings, much evil and