Изображения страниц
PDF
EPUB

Phil. Transactions for that year. His object was | Dr. Wollaston illuminated his objects, not with to get rid of unnecessary light which impeded rays of light which were actually converged upon vision, and not to remove the evils arising from the object, but with rays diverging from a point diffraction. Dr. Wollaston never once mentions between the object and the illuminating lens; and diffraction, or any other cause, but that of super- it is obvious, from his recommendation to use at fruous light; as the origin of imperfect vision aris- night a common bull's-eye lanthorn, that he had no ing from the usual modes of illumination. He idea whatever of the necessity of bringing the rays was not aware, indeed, that the diffraction of the to a focus upon the object with such accuracy that light used for illumination was the evil to be cor- they should again radiate from it as if it were rected, and he has accordingly not corrected it by self-luminous. His object seems to have been his apparatus. “In the illumination of micro- solely to get a distinct and equally illuminated dise scopic objects,” says he," whatever light is cor- of light of no greater diameter than what was rected and brought to the eye beyond that which is necessary for seeing the object; for no illumination fully commanded by the object-glasses, tends rather of the smallest value can be obtained unless by w impede than to assist distinct vision. My lenses free from chromatic and spherical aberration, endeavor has been to collect as much of the admit- or of such a short focus, from the 20th to the 80th ted light as can be done by simple means to a focus part of an inch, that the effects of aberration become in the same place as the object to be examined. almost inappreciable. For this purpose I have used with success a plane How M. Chevalier could have so far misundermirror to direct the light, and a plano-convex lens stood the purport of this criticism on Dr. Wollasto collect it.” In describing the apparatus itself, ton's method, as elsewhere indicated,* we cannot he says that this “plano-convex lens, or one prop- conjecture. There is no doubt that Dr. Wollaserly crossed, (that is, its radius 1-6 or 6-1,) to have ton's figure, namely, fig. 1, of his plate, is quite the least aberration, should be about three quarters incorrect, as M. Chevalier states; but the criticism of an inch focus, having its plane side next the was not founded on the erroneous figure, as he object to be viewed, and at the bottom is a circular supposed, but on the description of the apparatus perforation A, of about three tenths of an inch in the text; and we have no doubt that M. Chevdiameter, for limiting the light reflected from the alier, should this notice meet his eye, will acknowlplane mirror, and which is to be brought to a focus edge that he has entirely misapprehended Dr. at a, (the place of the object,) giving a neat image Wollaston's method of illumination, and has not of the perforation A, at the distance of about 8- appreciated the method of Sir David Brewster, 10ths of an inch from the plano-convex lens, and which he supposed it to resemble. To make light in the same plane as the object which is to be radiate from an object seen in a microscope of any examined.

For the perfect per- reasonable magnifying power, by means of a planoformance of this micr&scope, Dr. Wollaston adds, convex lens, or a properly crossed lens of 3-4ths it is necessary that the axis of the lenses, and the of an inch focus, and 3-10ths of an inch in diamecentre of the perforation should be in the same ter, would be as absurd as to expect to see the right line. This may be known by the image of satellites of Saturn through an opera-glass; and the perforation being illuminated throughout its still more absurd is it when the object is illumi. whole extent, and having its whole circumference nated by rays whose conjugate focus is the centre equally well defined. For illumination at night, a of a perforation within two or three inches of the common bull's-eye lanthorn may be used with great lens, instead of being at very great or an infinite advantage.In the appendix to his paper, Dr. distance. Wollaston gives the following measurements and It is in vain to expect from the microscope that unequivocal directions for the adjustment of his scrutiny of minute objects which it is fitted to give illuminating lens. “ The position of the lens may till it is furnished with an illuminating apparatus be varied so as to bring the image of the perfora- as perfect as its magnifying apparatus—a combition* into the same plane with the object to be nation of powers which requires the microscope to viewed.

Supposing the plano-con- be fitted up in a manner quite different from what vex lens (the illuminating lens) to be placed at its it is at present. proper distance from the stage, the image of the The fourth treatise placed at the head of this perforation may be readily brought into the same notice contains some excellent and useful observaplane with the object, by fixing temporarily a tions on simple and compound microscopes. The small wire across the perforation with a bit of wax, pancratic microscope, which it is the principal viewing any object placed upon a piece of glass object of the treatise to describe, differs from upon the stage of the microscope, and varying the others, in so far as it admits a successive increase distance of the perforation from the lens by screw- of magnifying power without changing either the ing its tube until the image of the wire is seen dis- eye-piece or object-glass. This is effected by tinctly at the same time with the object upon the using an eye-piece consisting of four lenses, two piece of glass.” Hence it is demonstrable that of which next the eye can be separated by a drawCOMPOUND ACHROMATIC MICROSCOPE-MAN'S LOVE-WOMAN'S LOVE. 231 the Imperial Academy of Sciences at St. Peters

tube from the other two lenses. In a report on * That is the conjugate focus of the perforation, con- Professor Fischer's microscope by a committee of sidered as a circular object, from which rays diverge-not the conjugale focus of the rays which pass through the

* See Edinburgh Journal of Science, New Series, No. perforation.

XI., p. 83, Jan. 1832.

MAN'S LOVE. burg, the merit of this invention, as applied to tel

Oh! Fanny, do not sigh for me,escopes, is ascribed to Sir David Brewster, who

I shall not sigh for you ; took out a patent for it in 1812, and published an With heart unfettered, light and free, account of it in his treatise on New Philosophical I smile a last adieu. Instruments. The report speaks favorably of its Though strewed with flowers the sportive hours application to the microscope, the credit of which With Fanny that flew by,

I could not stay another day, belongs to Mr. Fischer, and we have no doubt

For India's gold—not Ithat for many purposes such an instrument would

For still my bounding heart is free, be useful; but as there is only one position of the

And longs for something new; two parts of the eye-piece in which the achroma- Then, Fanny, do not sigh for me, tism is most perfect, a variation of magnifying I shall not sigh for you! power would be better obtained by the use of dif

The bird that hath not built its nest, ferent eye-pieces, as in our best microscopes.

Is not more free than I;

The butterfly is not more blest,-
From the N, Y. Literary World.

From sweet to sweet I fly.
A COMPOUND ACHROMATIC MICROSCOPE, MADE My pathway lies through sparkling eyes,
BY AN AMERICAN ARTIST.

I count them o'er and v'er;

Each dawning light appears more bright We have lately had the pleasure of examining a

Than that which shone before! microscope of high power, with some account of

For ah! to love them all I'm free, which our readers may be interested, both for the

(I'll use that freedom too !) actual merit of the instrument, and for the circum

Then, Fanny, do not sigh for me,stances under which it was made.

I shall not sigh for you! Mr. Charles Spencer, of Canastota, in this state,

Sharpe's Magazine. visited our city about a year ago, and had, through the kindness of a professor in one of our schools of medicine, an opportunity of examining a microscope

WOMAN'S LOVE. made by Chevalier, of Paris, under the orders of the celebrated Jussieu, of the Garden of Plants. Mr.

“ Thy home is not so bright, Ladye, Spencer had never seen one of these instruments

As it was wont to be ; before, but, after careful examination, he surprised

Thine eyes have lost their light, Ladye, the professor, hy remarking, with all the simplest

Thy laugh its ringing glee. confidence imaginable : “I could make a better Thy step is sad and slow,microscope than that." The person to whom this Thy faltering accents fail; boast was made, often, during the next six months,

Alas! that tears should flow amused his friends with the Yankee presumption

Down cheeks so young and pale ! of the backwoods artist, who so confidently claimed

Thou wert not once so sad and strange ;superiority over the first optician in France. The Oh! what has wrought this wondrous change ?" jest lasted but six months, however, for, at the end

“Mine eyes are like the moon, Pilgrim,
of that time, the professor was invited to examine
two lenses, one of high power, made by Mr. Spen-

They shone with borrowed light ;
To his unbounded astonishment, they proved

My cheek, like flowers of noon, Pilgrim,

Grows pale with coming night. to be of the highest order of excellence, and, as a reward to native ingenuity, he ordered a microscope

My voice is like the bird from Spencer, to be modelled after those of Chev

That greets the op'ning day; alier, and of course as much better as the native

My laugh is only heard could make it. This instrument has just been

When this poor heart is gay: completed and placed in the hands of the owner.

Oh! when the sun has left the sky,

The earth is dark-and so am I!" It has already been examined by Professor Bailey, of West Point, who has no superior as a “ The sun is shining bright, Ladye, microscopist in this country; by Prof. Torrey, who Down from the summer skies; had long been in the habit of using one of Cheva- The flowers that sleep at night, Ladye, lier's best instruments ; by Prof. Clark, Dr. Gil

Now ope their smiling eyes. man, and others of our savans, who all unite in

The birds are singing now, pronouncing it excellent. Prof. Bailey says it is

With free exulting voice; " decidedly superior to Chevalier's,' and adds, that

Nature is glad—and thou,he could do all with it that he could with the Low

Why dost not thou rejoice? ell instruinent at Boston.

Look up, and greet the sun's bright beamThus has one of our countrymen, self-taught,

Feel that of night thou dost but dream." and almost without experience, (for Spencer has made but very few instruments, and not one on the “ That dream is in my heart, Pilgrim, model of this,) taken his place beside the oldest It lieth there so deep, and most experienced opticians of Europe. We It never will depart, Pilgrim, are happy to hear that he is already reaping the A wake, nor yet in sleep : fruit of his labors. Prof. Henry, of the Smithso- A dream of severed ties, nian Institute, has ordered a large instrument, on Of love so fond—so vain ; which, we doubt not, all his talents will be dis- Of words, and smiles, and sighs, played-Dr. Clark two-and others, we doubt not, That will not come again! will follow. No man nersl hereafter import a for- My sun, alas! was not in heaven: eign instrument. We can add these to the number Its light from human eyes was given !” of our domestic manufactures.

cer.

THE MILITARY CLASS.

She once had a feudal standing army to repel the The Philadelphia Public Ledger thus states a doctrine Scots, while the Scots had one to repel the Engwhich seems to be growing very fast:

lish. The union of the two neighbors removed Some of the journals express apprehensions this necessity; and now, standing armies to proabout the creation of a military class, or standing tect one against the other, would be as useless as arıny, as ultimately fatal to our republic. They they would between New York and Pennsylvania. refer to the wishes expressed by the most intelligent So far, England and Scotland are like the United of the Mexican population, for the continued occu- States. But England has numerous conquered pation of their country by our armies, to protect dependencies, which she must protect against other them against their own, as something quite signif- nations, or keep in order towards herself, by standicant of the future to ourselves. They ask what ing armies. Here she has something like contiwe should think, if compelled to seek the protection nental subdivision, and consequently something to of foreign bayonets against our own armies ; and fence against. they say that this will come, if we create a numer- Then to remove all necessity for standing armies, ous military class.

we must have no neighbors to fence against, or, in Though going as far as any journal in hostility other words, we must extend our confederacy over to standing armies, we do not participate in these the continent. In other words, we must conquer, apprehensions. We regard the annihilation of absorb Mexico. But these journals object to the Mexican nationality, the annexation of Mexico to annihilation of a sister republic. Do they believe our own republic, as a measure which will ul- that this sister republic will ever be our ally and timately remove all necessity for standing armies. coöperator against Europe ? A rival, hostile race, The standing armies of continental Europe are a they will be our enemies under any circumstances, vecessity of its national subdivision. These Eu- and therefore impose upon us the necessity of ropean nations, separated by merely conventional, building the military fence. But will Mexico connot natural boundaries, must fence against each tinue a republic ? By no means. The European other with standing armies. And as popular governments will impose monarchy upon it, and governments and standing armies are entirely in- make monarchy an instrument of its renovation, compatible, their governments must be despotisms till it becomes, like France or England, a powerof some kind.

We despair of free governments in ful nation, with large fleets and armies, a rich arisContinental Europe, till its standing arinies disap- tocracy and a poor people. And they will do this pear, and we despair of this disappearance till the to force us into standing armies against Mexico. European nations are incorporated in some confed- They know that our prosperity and power flow from eracy. Universal empire, under some federal sys- our republicanism. They would dry up its source; tem, has been a favorite project with some of its and they know that this republicanism must soon great men, who saw in advance of their age, and wither under an expensive nilitary government, especially with Henry IV. of France. But the and that an expensive military government will beattempts at universal empire made by some of come a necessity with us, when Mexico is made a its great military geniuses, and especially Na- powerful military monarchy. poleon, did not look beyond the aggrandizement of But the journals tell us that this conquest of himself and his family. Why, then, are free gov- Mexico renders large armies necessary, and that ernments a moral impossibility in Continental Eu- when the conquest is completed we cannot disband rope? The superficial reply, “ Because European the armies. Indeed ! Congress have constitutional nations have standing armies.” But the far-seeing power enough for it, and the people will have the reply, “ Because it is subdivided into different na- will. That a hundred thousand soldiers should tions, which must fence against each other with be formidable to twenty millions of the most milstanding armies." By removing the standing ar- itary people in the world, is a proposition that we mies, we shall remove the despotism. Granted. can hardly meet seriously. Would Pennsylvania But to remove the standing armies, we must first be intimidated by her two regiments ?

Were they remove the national subdivision.

ten, the state has a few more left of the same sort, Applying this doctrine to our own continent, we competent to extinguish them on any day, in voting say that with neighbor nations to fence against, we or fighting republicans must have standing armies. But with But in taking Mexico we shall take an Ireland. a confederacy covering the whole continent, and Yes, if we are unwise enough to follow the Engnothing but the continent, we shall have no national lish example, and keep it a distinct and hostile deneighbors, and therefore nothing against which to pendency, for the benefit of an aristocracy at home. raise military fences. Even England, an European But we shall avoid all this, and make it another nation, illustrates this doctrine, when contrasted Louisiana, by pursuing the Russian policy of introwith Continental Europe, and also when contrasted ducing our own laws, language, and customs, and with our

own country. England, safe against thus rendering Mexico Anglo-American. Continental Europe by the natural barrier of the By extending our confederacy over the continent, ocean, needs no standing armies at home. When the whole continent, and nothing but the continent, invasion is threatened, her intelligent and energetic we shall ultimately remove all of a military class, population become a standing army for the crisis. and shall thus preserve our liberties.

From the Journal of Commerce.

THE BENEFACTOR OF AN EMPIRE.

the whole was completed in six quarto volumes, in 1823, at an expense of £ 12,000.

While the Dictionary was going through the While scores of worthless, if not injurious, vol

press, the Old Testament was progressing by the umes, are, in this book-making age, sent out every joint labors of Dr. Morrison and Mr. Milne, and in month into the community, it is truly gratifying to Nov., 1818, the entire Bible was published. In meet with such a work as “ The Chinese Empire,

the mean time Dr. Morrison had also published, by Williams, just issued from the press of Wiley both in Chinese and English, a tract on Redemp& Putnam. From the great amount of valuable tion, a trauslation of the Assembly's Catechism and information contained in these two octavo volumes, Liturgy of the Church of England, a Synopsis of the following facts are selected respecting the the Old Testament History, a hymn-book, a Tour labors of Dr. Morrison, the first Protestant mis- of the World, and a few essays on religious subsionary to China.

jects. Of these several works nearly thirty thouHe received his appointment from the London sand copies were distributed. In 1815 he published Missionary Society in 1807, and proceeded imme

a Chinese grammar; and also a small volume of diately to Canton, by way of New York; the dialogues in English and Chinese, and a volume East India Company at that time refusing pas- entitled View of China in 1817. sage in their ships to all missionaries, either to

Dr. Morrison accompanied Lord Amherst to India or China. During the first year he lived in Peking in 1816, as interpreter to the embassy ; a roon of the factory of Messrs. Milner & Bull, the return journey through the country affording of New York, devoting his whole time to the study him opportunity of collecting much valuable inforof the language. China was then a sealed coun

mation. try to missionaries.

In 1824, Mrs. M. having died three years preIn consequence of commercial difficulties in vious, Dr. Morrison returned to England, where 1808, he was obliged, with all British subjects, to he was honorably received, presented to his leave Canton and repair to Macao. There, in

majesty George IV., and warmly encouraged by 1809, he accepted the appointment of translator to all'interested in the advancement of religion and the East India Company ; an office which furnished learning. He published a volume of sermons him all necessary security, so that he could prose- while in England, formed a second matrimonial cute his work with diligence and confidence ; at the connection. and returned to China in 1826. From same time his salary was sufficient for the sapport this time till his death in 1834, though chiefly of his family, and enabled him to proceed in his occupied by his duties as translator to the Company, studies, with but little expense to the society. he published a Vocabulary of the Canton Dialect, The translation of the Scriptures, and the printing in two volumes, for the use of foreign residents and publishing of his numerous works, says the and seamen in their intercourse with the Chinese ; author, could hardly have been carried on, at that also a Miscellany of useful information, in four time, without the countenance and aid of that pow- volumes, and three or four smaller works ; a erful and wealthy body.

Selection of Scriptural Lessons, a second edition In 1810 the Acts of the Apostles were issued of the Psalter and Liturgy, and a volume of hymns by Dr. Morrison—the first portion of the Bible

and prayers. printed in Chinese—followed in 1812 by the Gos

He died at the age of 52, having spent twentypel of Luke; on each of which occasions the B.

seven years of missionary labor in China, and and F. Bible Society granted five hundred pounds

most of that time alone. After all his toil, and to assist in the prosecution of the work. In 1814

faith, and prayer, he saw only three or four conthe whole New Testament was published, about

verts, no churches, schools, or public congregahalf of it having been translated entirely by Dr. tions, yet he was not discouraged. In his last M., and the remainder revised by him from a man- letter he says, “I wait patiently the events to be uscript found in the British Museum.

developed in the course of Divine Providence. The leading objects of the society, in sending The Lord reigneth." Few men have ever accomDr. Morrison to China, were the translation of the plished so great an amount of labor, or, as Bible and the preparation of a Dictionary, with

pioneer, done so much to prepare the way for such additional labors in preaching, teaching, and writing tracts, as he found leisure and opportunity evangelizing millions of the human family. to perform.

DOG-CHASE. The compilation of the Dictionary progressed so well, that in the same year Mr. Elphinstone, Sir We beg to suggest that when provision is made George Staunton, and a few others of the E. I. by congress for taking the next census of 1850, Company's establishment in China, interested them- it shall be made the duty of the United States marselves in getting it printed, and for this purpose shals and their deputies to take down the number applied to the Court of Directors in London, who, of the dogs in the country; which, notwithstandsensible of the importance of the undertaking, ing the extensive interest of the subject, is one on responded on the most liberal scale, and sent out a which the universal American people, who know printer and a printing office. The first volume, everything, know nothing. Who can tell how of near a thousand pages, was issued in 1817, and many dogs we have in the United States—or who

a

coun

can guess ? Fifteen millions of horned cattle, the various points of his visitation, as to raise a twenty millions of sheep, thirty millions of hogs ; doubt whether one dog, however ferocious and these are ascertained numbers—but how are we to determined, could accomplish so large an amount deduce from then the canine population? The of mischief. One morning the owner of a fine Farmers' Library, of this month, speaking of the flock would ascertain that several of his choicest late Nathaniel Macon, says, he told the editor “he sheep were lying killed in his fold, and himself would not live where there was a law against some thirty or forty pounds the poorer ; and the dogs," and declared that “ each of his negroes next, a farmer so many miles distant as to warrant kept one, and that he kept thirteen." This might his fancying himself out of harm's way, would give us the means of striking some average for the discover himself in a similar position, from the dogs of the southern states ; but the object is to totally unexpected visit of this ruthless destroyer. find the numbers for the whole country.

To such a height had the ravages of the brute We think it would be a very moderate basis of proceeded during an entire month, that the computation to allow one dog to every family in try side” literally rose in arms” against him. the United States. This would give us, in round Nearly a hundred sheep had he torn the throats numbers, about five millions of dogs; each of which, of, and though seen now and then at a distance, living on garbage and offal, consumes annually the he never would allow a single person to come food that would raise a pig, worth one dollar. The within gun-shot range of him. He was undercost of feeding our dogs in the United States is, stood to be dark-colored, of unusual size, and swift therefore, $5,000,000 a year, and their existence is of foot; but that was all, and doubts were entera dead loss to the nation, annually, of that amount. tained as to whether it really was a dog or not,

But how many millions of dollars are lost by many being inclined to believe, from the descripthe sheep destroyed every year by dogs? That tion given of it, that it might be some wild beast is an item which no man can compute, until con- escaped from a travelling menagerie. gress shall choose to direct the attention of the Certain it is that its appearance, in a country so census-takers to the subject. It will, undoubtedly, thinly populated, and so quiet and retired, and the turn out, when ascertained, to be a great and pro- destruction that attended its path, gave rise to many digious loss. Few persons are aware of the havoc stories more creditable to the imagination than to which a single bad dog can make among a flock the judgment of the narrators. The excitement of sheep in a few moments. We have been told created naturally increased with every further acthat Major Raybold, of Delaware, computes his count of the animal's deadly visits; and at length individual losses in this way, notwithstanding every the farmers of the district felt themselves compelled care to prevent them by shepherds, watch-dogs to set watches over their flocks every night; or to and poison, at upwards of three thousand dollars ; house every sheep, at whatever inconvenience, beand we learn that one of his enterprising sons lost, fore dusk. Those who know the country of which last week, in a single night and by a single dog, we speak, the perfect security which is felt as to eighteen or twenty sheep of an improved stock, any attacks on property, and the great difficulty worth ten dollars a head. We have cut from our the farmers generally would have in obtaining asEnglish files an account of a canine “ sheep-sistance to keep night watches, or in finding room stealer," who seems, for a time, to have threat in their outbuildings at this time of the year for ened the ruin of all the sheep farmers near Preston. anything like a flock of sheep, however small,

It is clear that “man's most faithful friend" is will readily understand the desire which was unirather a costly one; and when we add the danger versally felt to rid the country of a visitor who and loss of human life from hydrophobia, one is caused so much annoyance, anxiety and fear. In more disposed than ever to ask why the paternal the early part of last week the farmers of the counattention of the government should not be directed try turned out far and near, to the number of uptowards the enumeration and general statistics of wards of a hundred, armed with guns, pitchforks, this branch and class of our animal population.—&c., and completely scoured the district in search American I Gazette.

of their enemy, but without effect. On Saturday CHASE OF A SHEEP-Slayer.-Extraordinary night week it was found that he had killed twelve losses have recently been suffered by the farmers sheep, at Beacon-fell-side ; and on the Sunday in the district north of Preston, from the remarka- following three or four hundred persons were on ble sheep-killing propensities of a large and fierce the hunt for the destroyer. In the course of the dog, which roamed over the country at night, day, Mr. Logan, of Barton, got a distant shot at slaughtering sheep in every direction, and escap- a large dog by the side of Barton mill, supposed ing by some unaccountable means the numerous to be the one all were looking for, but the animal snares which were set to compass its capture, dead escaped unhurt. That night he killed fifteen sheep or alive. Night after night did this mysterious at Catterall-hall. On Wednesday, at day break, brute pursue his course, creating alarm in every the brute was seen in the act of tearing a sheep's direction, and seemingly defying any attempt to throat out at Woolfell's-mill, having five others check the mischief he was making. No farmer's lying dead about him. The cry was immediately flock, in the wide district he selected as the scene raised; all within hearing turned out, with such of his ravages, was safe from his attack; while weapons as could be seized in the hurry and exhe occasionally placed so great a distance between citement of the moment; and the start was com

« ПредыдущаяПродолжить »