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One of the defects of Daguerreotype, been found disagreeable in Daguerreas applied to portraiture, arises from otype portraits. This is effected by the impossibility of bringing the en- colouring them by means of dry cotire person of the sitter at once into lours rubbed into the incisinns made focus. To render this possible, it by the action of the light. These would be necessary that every part of coloured Daguerreotypes, though more the person of the sitter should be at open to objection on artistical grounds, precisely the same distance from the are, nevertheless, decidedly jopular, lens of the camera obscura, a condition when judiciously executed. which obviously cannot be fulfilled. Artists, and especially miniatureIt happens, consequently, that those painters, are naturally opposed to parts of the person of the sitter which Daguerreotype. No miniature, how. are nearest to the lens, will be repre- ever, will, so far as relates ti mere sented on a scale a little greater than resemblance, bear comparison to a those parts which are most distant; Daguerreotype. The artist can soften and if the instrument be adjusted so as down defects, and present the sitter to bring the nearer parts into very

under the most favourable aspect. exact focus, the more distant parts The sun, however, is no flatterer, and will be proportionally out of focus. gives the lineaments as they exist, with

These defects cannot be removed, the most inexorable fidelity, and the but may be so much mitigated as to be most cruel precision. imperceptible. By using larger lenses, Nevertheless, it is known that some the camera can be placed at a consider- of the most eminent portrait-paintersable distance from the sitter, without those whose productions have raised inconveniently diminishing the size of them above petty feelings-do avail the pictuitPj this expedient, the themselves of the aid of Daguerreodifference between the distances of types, where well.executed represen. different points of the sitter from the tations of that kind are obtainable ; lens, will bear so small a proportion to and they see in this no more degrathe whole distance, that the amount of dation of their art, than a sculptor distortion arising from the cause just finds in using a cast of the subject mentioned may be rendered quite im- which his chisel is about to reproduce. perceptible. Large lenses, however, But of all the gifts which Science when good in quality, are expensive ; has presented to Art in these latter and it is only the more extensively- days, the most striking and magnifi. employed practitioners in this business cent are those in which the agency of that can afford to use them.

electricity has been evoked. The magnitude of these pictures From the moment electric phenowill, in a great degree, depend on the mena attracted the attention of the magnitude of the lens. We have scientific world, the means of apply. seen, lately, groups executed by a ing them to the useful purposes of Parisian artist, on plates from fifteen life were eagerly sought for. Although to sixteen inches square.*

such applications had not yet entered The agency of light and shade has into the spirit of the age as fully as been successfully used, in the same they have since done, it so happened manner, to produce pictures on paper, that, in this department of physics, a glass, wood, and other substances, volunteer had enlisted in the army of chemically prepared, so as to be more science, the characteristic of whose or less impressed with some dark co- genius was eminently practical, and lour. The representations obtained soon achieved, by his discoveries, an in this manner have not, however, the eminence to which the world has since precision and distinctness which are so offered universal homage. Benjamin universally characteristic of the Da- Franklin, a member of a literary guerreotype process.

society in Philadelphia, had his attenAttempts have been recently made, tion called to the then recent diswith more or less success, to remove covery, the phenomena of the Leyden the metallic or leaden bue which has Jar, which at that time astonished all

The most successful practitioner in Daguerreotype now in Paris is Mr. W. Thompson, an American.

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electricity ing this, wrote to one of his friends in ile toucher

Philadelphia :high the prothe electric “The king's changing his pointed conit once to

ductors for blunt ones is a matter of small , or “light. importance to me. If I had a wish about otection of

them it would be that he would reject them Slings be so,"

altogether as ineffectual. For it is only siuce he thought himself and his family safe from the thunder of heaven that he has dared to

use his own thunder in destroying his inno? jn preserving

cent subjects.”+ ni the stroke **" to fix on the Art often presses into its service the ???s upright rods

discoveries of Science, but it sometimes 38qwerble, and gilt (at provokes them. Art surveys the fruit is; and from the

of the toil of the philosopher, and sein the outside of

lects such as suits her purposes ; but ?, or down round

sometimes, not finding what is suitable , and down her tir? Would not

to her wants, she makes an appeal to bly draw the electric

Science, whose votaries direct their re it came nigh

researches accordingly towards the barby secure us from desired objeci, and rarely fail to attain irrible mischief."* them.

One of the most signal examples of jiny one, that after

the successful issue of such an appeal livied his theory by presents itself in the safety-lamp. minent of the kite, The same gas which is used for the ully drained a cloud purposes ofillumination of our cities and ; but what is not so towns (and which, as is well known, is int when the paper

obtained from coals by the process of klin, explaining his baking in close retorts) is often sponrneting lightning-con- taneously developed in the seams of protection of buildings, coal which form the mines, and collects wards read before the in large quantities in the galleries and

of London, it was re- workings where the coal-ininers are is of laughter, and was employed. When this gas is mingled and as to be deemed un. with common air, in a certain definite Disa printed in the “ Phi. proportion, the moisture becomes highvansactions.” It was, how- ly explosive, and frequently catastro

i by an independent pub. phes, attended with frightful loss of life, į has attained, as is well occurred in consequence of this in the world-wide celebrity. mines. The prevalence of this evil at ng afterwards, the same length became so great, that govern

of the Royal Society who ment called the attention of scientific at Franklin's project, were men to the subject, and the late Sir pon to superintend the erec- Humphrey Davy engaged in a series

onductors upon the royal pa- of experimental researches with a view

hen, to gratify the royal spleen to the discovery of some efficient prood odhit the rebellious philosopher of tection for the miner, the result of

:. Solted colonies, they rejected the which was, the now celebrated safety. spil conductors recoinmended by lamp. ..nklin, and actually caused blunt Davy first directed his inquiries to cwaductors to be placed on the palace. the nature and properties of fame. Franklin, who held the office of Ame. What is flame ? was a question which rican Minister in London (the inde. seems until then never to have been pendence of the United States being answered or even asked. ihen recently acknowledged), on hear- All known bodies, when heated to a

* " Franklin's Works," vol. v. p. 235. Boston: 1837.
† " Franklin's Works," vol. v. p. 227.

Europe. From that moment the craving after utility was the great views of Franklin were bent on the characteristic of his mind, and may discovery of some useful purpose to even be regarded as having been car. which these discoveries could be ap. ried almost to a fault. It has been plied. Cui bono? was a question never justly observed by a contemporary absent from his thoughts. After hav

writering made some of those great dis

“That although the application of the procoveries which have since formed the

perties of matter and the phenomena of basis of electrical science, and have nature to the uses of civilised life is unsurrounded his name with unfading doubtedly one of the great incentives to the lustre, he expressed, in a letter to the investigation of the laws of the material secretary of the Royal Society of Lon- world, yet it is assuredly a great error to redon, in his usual playful manner, his gard that either as the only or the principal

motive to such inquiries. There is in the disappointment at not being yet able to find any application of the science be.

perception of truth itself—in the contempla

tion of connected propositions, leading by the neficial to mankind :

mere operation of the intellectual faculties,

exercised on individual physical facts, to the “Chagrined a little,” he wrote, “that we

development of those great general laws by have hitherto been able to produce notbing which the universe is maintained-an exalted in the way of use to mankind; and the hot

pleasure, compared with which the mere weather coming on, when electrical experi- attainment of convenience and utility in the ments are not so agreeable, it is proposed to

economy of life is poor and mean. There is put an end to them for the season, some- a nobleness in the power which the natural what humorously, in a party of pleasure, on philosopher derives from the discovery of the banks of the Schuylkill.* Spirits, at the

these laws, of raising the curtain of futurity same time, are to be fired by a spark sent and displaying the decrees of nature, so far from side to side, through the river, without

as they affect the physical universe for countany other conductor than the water; an ex- less ages to come, which is independent of, periment which we some time since per- and above all, utility. While, however, we formed to the amazement of many:t A thus claim for truth and knowledge all the turkey is to be killed for dinner by the elec

consideration to which, on their own account, trical shock, and roasted by the electrical

they are entitled, let us not be misunderstood jack, # before a fire kindled by the electrical

as disparaging the great benefactors of the bottle (since known as the Leyden phial), human race, who have drawn from them "when the healths of all the famous elec

those benefits which 30 much tend to the tricians in England, Holland, France, and

well-being of man.

When we express the Germany, are to be drunk in electrified

enjoyment which arises from the beauty and bumpers, under the discharge of guns from fragrance of the flower, we do not the less the electrical battery."S

prize the honey which is extracted from it,

or the medicinal virtues which yields. Altbough the application of the great That Franklin was accessible to such feelings, principles of science to the practical the enthusiasm with which he expresses uses of life cannot be too highly appre- himself throughout his writings, in regard ciated, it would be a great error to

to natural phenomena, abundantly proves. carry this enthusiasm for the useful to Nevertheless, useful application was such an excess as to exclude a just ad

doubtedly ever uppermost in his thoughts; miration for those high abstract laws,

and he probably never witnessed a physical

fact, or considered for a moment any law of the discovery of which had conferred

nature, without inwardly proposing to himlustre on the names of our greatest self the question, “In what way can this be philosophers, and on none more justly made beneficial in the economy of life.' ” || than that of Franklin himself. It must be admitted, however, that this After studying the properties of

un

* A picturesque river which washes the Western suburbs of Philadelphia, and to the valley of which it is the custoin of the citizens to make pic-nic parties. In the summer months, the temperature at Philadelphia is so high as to banish to the watering-places all who are not abolutely tied to the town by the exigencies of their business.

+ This experiment has been recently reproduced in the investigations connected with the electric telegraph, but without giving credit to Franklin as its original author.

$ It will be seen by this hint that the idea of applying electricity, as a moving power, had already occurred to Franklin. & Franklin's Works, vol. v. p. 210. Boston : 1837.

"Lardner on Electricity and Magnetism,” vol. i. p. 41.

metali, in virtue of which electricity ing this, wrote to one of his friends in runs along them in preference to other Philadelphia :substances, and discovering the property of points to attract the electric " The king's changing his pointed confluid, Franklin proceeded at once to

ductors for blunt ones is a matter of small the discovery of conductors, or “light:

iinportance to me. If I had a wish about ning rods," for the protection of

them it would be that he would reject them buildings. • If these things be so,"

altogether as ineffectual. For it is only siuce wrote he

he thonght himself and his family safe from

the thunder of heaven that he has dared to “May not the knowledge of this power

use his own thunder in destroying his innoof points be of use to mankind in preserving

cent subjects.”+ houses, churches, ships, &c., from the stroke of lightning, by directing us to fix on the Art often presses into its service the highest points of those edifices upright rods discoveries of Science, but it sometimes of iron made sharp as a needle, and gilt (at provokes them. Art surveys the fruit the points) to prevent rusting ; and from the of the toil of the philosopher, and sefoot of those rods a wire down the outside of lects such as suits her purposes ; but the building into the ground, or down round

sometimes, not finding what is suitable one of the shrouds of a ship, and down her side till it reaches the water? Would not

to her wants, she makes an appeal to these pointed rods probably draw the electric

Science, whose votaries direct their fire out of a cloud before it came nigh

researches accordingly towards the enough to strike, and thereby secure us from desired object, and rarely fail to attain that most sudden and terrible mischief."* them.

One of the most signal examples of It is known to every one, that after the successful issue of such an appeal this Franklin established his theory by presents itself in the safety-lamp. the celebrated experiment of the kite, The same gas which is used for the hy which he literally drained a cloud purposes ofillumination of our cities and of its lightning ; but what is not so towns (and which, as is well known, is well known is, that when the paper obtained from coals by the process of written by Franklin, explaining his baking in close retorts) is often spon. project of constructing lightning-con- taneously developed in the seams of ductors for the protection of buildings, coal which form the mines, and collects was soon afterwards read before the in large quantities in the galleries and Royal Society of London, it was re- workings where the coal-miners are ceived with peals of laughter, and was employed. When this gas is mingled voted so absurd as to be deemed un- with common air, in a certain definite worthy of being printed in the “ Phi. proportion, the moisture becomes highlosophical Transactions.” It

was,

how- ly explosive, and frequently catastroever, printed by an independent pub. phes, attended with frightful loss of life, lisher, and has attained, as is well occurred in consequence of this in the known, a world-wide celebrity.

mines. The prevalence of this evil at Not long afterwards, the same length became so great, that governmembers of the Royal Society who ment called the attention of scientific laughed at Franklin's project, were men to the subject, and the late Sir called upon to superintend the erec- Humphrey Davy engaged in a series tion of conductors upon the royal pa- of experimental researches with a view lace, when, to gratify the royal spleen to the discovery of some efficient proagainst the rebellious philosopher of tection for the miner, the result of the revolted colonies, they rejected the which was, the now celebrated safety. pointed conductors recommended by lamp. Franklin, and actually caused blurt Davy first directed his inquiries to conductors to be placed on the palace. the nature and properties of flame. Franklin, who held the office of Ame. What is flame? was a question which rican Minister in London (the inde. seems until then never to have been pendence of the United States being answered or even asked. ihen recently acknowledged), on hear- All known bodies, when heated to a

* “Franklin's Works," vol. v. p. 235. Boston: 1837.
† " Franklin's Works," vol. y. p. 227.

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