On

and he could leave it in that way for hours together. being remonstrated with, he said, "It is quite good enough." Notwithstanding such difficulties as these, the experiment was considered satisfactory, but it was discontinued at the South Foreland, for the cliffs there are marked by a double light, and the electric spark was so much brighter than the oil flames in the other house, that there was no small danger of its being seen alone in thick weather, and thus fatally misleading some unfortunate vessel.

After this Faraday made further observations, estimates of the expense, and experiments on the divergence of the beam, while Mr. Holmes worked away at Northfleet perfecting his apparatus, and the authorities debated whether it was to be exhibited again at the Start, which is a revolving light, or at Dungeness, which is fixed. The scientific adviser was in favour of the Start, but after an interview with Mr. Milner Gibson, then President of the Board of Trade, Dungeness was determined on; a beautiful small combination of lenses and prisms was made expressly for it by Messrs. Chance, and at last, after two years' delay, the light again shone on our southern coast.

It may be well to describe the apparatus. There are 120 permanent magnets, weighing about 50 lbs. each, ranged on the periphery of two large wheels. A steam-engine of about three-horse power causes a series of 180 soft iron cores, surrounded by coils of wire, to rotate past the magnets. This calls the power into action, and the small streams of electricity are all collected together, and by what is called a "commutator" the alternate positive and negative currents are brought into one direction. The whole power is

M

then conveyed by a thick wire from the engine-house to the lighthouse tower, and up into the centre of the glass apparatus. There it passes between two charcoal points, and produces an intensely brilliant continuous spark. At sunset the machine is started, making about 100 revolutions per minute; and the attendant has only to draw two bolts in the lamp, when the power thus spun in the engine-room bursts into light of full intensity. The "lamp" regulates itself, so as to keep the points always at a proper distance apart, and continues to burn, needing little or no attention for three hours and a half, when, the charcoals being consumed, the lamp must be changed, but this is done without extinguishing the light.

Again there were inspections, and reports from pilots and other observers, and Faraday propounded lists of questions to the engineer about bolts and screws and donkey-engines, while he estimated that at the Varne light-ship, about equidistant from Cape Grisnez and Dungeness, the maximum effect of the revolving French light was equalled by the constant gleam from the English tower. But delays again ensued till intelligent keepers could be found and properly instructed; but on the 6th June, 1862, Faraday's own light, the baby grown into a giant, shone permanently on the coast of Britain.

France, too, was alert. Berlioz's machine, which was displayed at the International Exhibition in London, and which was also examined by Faraday, was approved by the French Government, and was soon' illuminating the double lighthouse near Havre. These magneto-electric lights on either side of the Channel have stood the test of years; and

for the last twelvemonth there has shone another still more beautiful one at Souter Point, near Tynemouth; while the narrow strait between England and France is now guarded by these "sentinels of peaceful progress," for the revolving light at Grisnez has been lately illuminated on this principle, and on the 1st of January of this year the two lights of the South Foreland flashed forth with the electric flame.1

In describing thus the valuable applications of Faraday's discoveries of benzol, of specific inductive capacity, and of magneto-electricity, it is not intended to exalt these above other discoveries which as yet have paid no tribute to the material wants of man. The good fruit borne by other researches may not be sufficiently mature, but it doubtless contains the seeds of many useful inventions. Yet, after all, we must not measure the worth of Faraday's discoveries by any standard of practical utility in the present or in the future. His chief merit is that he enlarged so much the boundaries of our knowledge of the physical forces, opened up so many new realms of thought, and won so many heights which have become the starting-points for other explorers.

1 The illuminating apparatus at Dungeness is one of what is termed the sixth order, 300 millimetres (about 12 inches) in diameter. Mr. Chance constructed one for Souter Point of the third order, one metre (nearly 40 inches) in diameter, with special arrangements for giving artificial divergence to the beam in a vertical direction, in order to obviate the danger arising from the luminous point not being always precisely in the same spot. It has also additional contrivances for utilizing the back light. Similar arrangements have been made for the South Foreland lights, which are also of the third order; and every portion of the machinery and apparatus is in duplicate in case of accident, and the double force can be employed in times of fog.

SUPPLEMENTARY PORTRAITS.

IT has been said that there is no photograph or painting of Faraday which is a satisfactory likeness; not because good portraits have never been published, but because they cannot give the varied and ever-shifting expression of his features. Similarly, I fear that the mental portraiture which I have attempted will fail to satisfy his intimate acquaintance. Yet, as one who never saw him in the flesh may gain a good idea of his personal appearance by comparing several pictures, so the reader may learn more of his intellectual and moral features by combining the several estimates which have been made by different minds. Earlier biographies have been already referred to, but my sketch may well be supplemented by an anonymous poem that appeared immediately after his death, and by the words of two of the most distinguished foreign philosophers-Messrs. De la Rive and Dumas.

"Statesmen and soldiers, authors, artists,-still
The topmost leaves fall off our English oak:
Some in green summer's prime, some in the chill
Of autumn-tide, some by late winter's stroke.

"Another leaf has dropped on that sere heap-
One that hung highest; earliest to invite
The golden kiss of morn, and last to keep
The fire of eve-but still turned to the light.

"No soldier's, statesman's, poet's, painter's name

Was this, thro' which is drawn Death's last black line; But one of rarer, if not loftier fame

A priest of Truth, who lived within her shrine.

"A priest of Truth: his office to expound

Earth's mysteries to all who willed to hearWho in the book of science sought and found, With love, that knew all reverence, but no fear.

"A priest, who prayed as well as ministered:

Who grasped the faith he preached, and held it fast : Knowing the light he followed never stirred,

Howe'er might drive the clouds thro' which it past.

"And if Truth's priest, servant of Science too,

Whose work was wrought for love and not for gain : Not one of those who serve but to ensue

Their private profit: lordship to attain

"Over their lord, and bind him in green withes,
For grinding at the mill 'neath rod and cord;
Of the large grist that they may take their tithes—
So some serve Science that call Science lord.

"One rule his life was fashioned to fulfil :

That he who tends Truth's shrine, and does the hest Of Science, with a humble, faithful will,

The God of Truth and Knowledge serveth best.

"And from his humbleness what heights he won! By slow march of induction, pace on pace, Scaling the peaks that seemed to strike the sun,

Whence few can look, unblinded, in his face.