The line from Malta to Alexandria is laid in sections by direction of the British government; the manufacturers would have preferred to make it a single continuous line. The gutta percha company of London also express full confidence in the successful working, and their readiness to guarantee this, of one of their manufacture. England is connected with the continent by 7 submarine cables. The line from Dover to Ostend, laid in 1852, is 75 m. long, and contains 6 wires. The lines laid in the Black sea in 1855, for communication between the Crimea and Constantinople, were in two sections, one from Constantinople to Varna, 200 m. long, and one from Varna to Balaklava, 150 m. These contained but one wire each. Their cost when laid was £22,000, and they worked with complete success. In 1857 a line was laid, at a total cost of £125,000, from Malta to Corfu in the Mediterranean, on which 400 m. of cable similar to that adopted for the Atlantic route was paid out. This is reported to have failed. The Dutch laid down a cable in 1861 between Batavia and Singapore, a distance of 660 m.; and after conveying a few messages it was several times broken by anchors or coral reefs, and was finally abandoned. The English government a few years since attempted the establishment of a line through the Red sea to connect the telegraphs in India with those of the Mediterranean. This proved entirely unsuccessful, never conveying even a single message throughout, and the project was abandoned, although the government had given a guarantee of 4 per cent. on £1,000,000 for half a century. A project to connect Falmouth in England with Gibraltar was abandoned after

the cable had been made for this purpose at a cost of £400,000. All these failures are explained chiefly through the neglect of the parties employed in laying the cables, and in no case through insuperable natural obstacles. The Atlantic cable was no doubt originally defective, and was injured beside, first in the way in which it was exposed to the sun, and afterward in the handling, and finally in the laying. Its weight was about 19 cwt. per mile. Some of the earlier cables were much heavier-even 7 tons per mile. For cables to lie in deep water, where no disturbance from anchors, currents, or drifting materials is likely to reach them, great weight beyond that required to sink them is considered of no especial advantage, and the heavy iron coating is found to be altogether useless; but near the shore cables of greater strength and weight are required to withstand the disturbing causes to which they are exposed. The principles of the electric telegraph are treated in many of the works on electricity, and the ablest papers upon this subject by the most eminent electricians are found in the volumes of the transactions of the scientific societies of Europe. Of the works specially devoted to this subject may be named "The Electro-Magnetic Telegraph, with Reports to Congress," by A. Vail (Philadelphia, 1845); "The Electric Telegraph, its History and Progress," by Edward Highton, C. E., a number of Weale's series (London, 1852); "Historical Sketch of the Electric Telegraph," by A. Jones (New York, 1852); "The Electro-Magnetic Telegraph," by L. Turnbull (Philadelphia, 1853); "The Telegraph Manual," by Tal. P. Shaffner (New York, 1859); and "History, Theory, and Practice of the Electric Telegraph,” by George B. Prescott (Boston, 1859).

TELEKY, or TELEKI, LÁSZLÓ, count, a Hungarian patriot, born in Pesth, Feb. 11, 1811, died there in the night of May 7-8, 1861. Belonging to a family distinguished by its possessions and connections in Hungary and Transylvania, as well as by political and literary merits, he early prepared himself for a political career, studying at Pesth and Patak, gained a reputation for rare attainments, contributed to political and miscellaneous periodicals, and in 1837 was elected a corresponding member of the Hungarian academy, of which his half brother Count Joseph Teleky (born 1790, died 1855), the author of the great history of "The Age of the Hunyadys," was the president. In 1842 he published his Kegyencz (“Favorite"), a drama, which has since successfully maintained itself on the stage. Having been for some years a member of the diet of Transylvania, he in 1843 took his seat in the upper house of that of. Presburg, where he soon became prominent for his eloquence, boldness, decided opposition to the rule of Metternich, and a consistent advocacy of liberal reforms. He subsequently became president of the "Opposition Club" at Pesth; and on the advent of his party to power in 1848 he was elected to the reorganized house

of representatives, in which he sided with the radicals. In Sept. 1848, he was sent as envoy of the Hungarian government to Paris, where he published Le bon droit de la Hongrie (1849), and zealously but vainly strove to gain the recognition by the French government of the independence of Hungary, on its proclamation at Debreczin. After the close of the Hungarian war, residing alternately in Paris, Brussels, and Geneva, he continued active in rousing the sympathies of the western nations for the cause of his country by contributions to the press, and in securing by personal representations the moral support of men of high standing. He gained easy access to the French court, during the war of 1859 was a member of the Hungarian national committee in Italy, and toward the close of the following year secretly repaired to Dresden. Here he was arrested by the Saxon police, and surrendered to the Austrian government, who 10 years before had sentenced him to death. The changed condition of affairs in that empire, however, made the execution of the sentence a political impossibility, and the emperor Francis Joseph, in a personal interview with the prisoner (Dec. 31, 1860), restored him to liberty on the promise of severing his connection with the Hungarian refugees and of abstaining for a time from political agitation. The returned exile was received by his countrymen with the liveliest demonstrations, and was soon elected by his former constituents to the newly convoked house of representatives. The diet was opened April 6, 1861, and the leader of the more moderate supporters of the laws of 1848, Francis Deák, prepared an address to the monarch, on which the debates were to open on May 8. Teleky, the leader of the radicals, who opposed any measure looking like a recognition of Francis Joseph as king of Hungary, and any advances on the part of the house toward a compromise, prepared an elaborate and statesmanlike discourse on the situation, in opposition to the address. This discourse was found on his desk, on the morning of the 8th, and near it on the floor the dead body of the writer, pierced by a pistol ball. Doubts on the expediency of his almost revolutionary policy, scruples concerning his word of honor pledged to the emperor, and bodily suffering are believed to have induced him to commit suicide. When the president of the house announced the catastrophe, several of its members burst into tears and the session was suspended. The debate on the address was commenced later, and after a protracted contest Deák's proposition was carried.

TELEMACHUS, a Greek prince of the heroic age, the son of Ulysses and Penelope. When Ulysses went to Troy, Telemachus was an infant, and in his father's absence he grew nearly to manhood. About the time that the gods had decreed the father's return home the son made an unsuccessful endeavor to eject the troublesome suitors for his mother's hand, and

then set out to seek information of his long absent parent. Accompanied by Minerva, who had assumed the appearance of Mentor, a faithful friend of his father, he visited Pylos and Sparta, and was hospitably received by Nestor and Menelaus. From Sparta Telemachus returned home, and on his arrival found his father with the swineherd Eumæus, disguised as a beggar. Their mutual recognition followed immediately, the suitors were slain or driven out, and Telemachus accompanied his father to the aged Laërtes. He is called by different authors the father of Latinus, and the founder of the town of Clusium in Etruria.

TELEOSAURUS, a genus of fossil crocodilians of the secondary epoch established by Geoffroy, differing from the living crocodiles in having biconcave vertebræ. The general form of the cranium was that of the gavials; the nostrils opened anteriorly at the end of the muzzle and posteriorly on a level with the jugal arch; the lower jaw was spoon-shaped at the end, with teeth on the sides like canines, the other teeth being small, equal, conical, and adapted for seizing a fish prey; the body was protected by larger and more solid plates, the anterior limbs were smaller, and the posterior more fin-like than in the present crocodilians. The strata which enclose their remains indicate a marine habitat, and their habits were probably those of the gavials. The genus has been divided by modern palæontologists into several subgenera, as given by Pictet. In the lias is found mystriosaurus (Kaup), having a very long muzzle, flattened head, and eyes directed upward. The T. (M.) Chapmanni (König), from the upper lias of Yorkshire, England, is described in the "Philosophical Transactions" of 1758; the vertebræ were 64, 16 being dorsal, and the teeth about 70 in each jaw; some of the dermal plates were 34 inches in their transverse diameter; it attained a length of about 13 feet. Macrospondylus (H. de Meyer) had longer vertebra and the S-shaped femur not longer than the leg; pelagosaurus (Bronn) had the eyes more widely separated, a shorter symphysis of the lower jaw, and the anterior limbs relatively small. The name has been generally restricted to the species found in the oolite, especially the T. Cadomensis (Et. Geoffr.), or crocodile of Caen, from the limestone of Normandy. This is characterized by large orbits near together, a flattened muzzle 5 times as long as wide, very long transverse processes of the dorsal vertebræ, and thick rectangular scales forming 10 regular series, each containing 15 or 16; it must have attained a length of 20 feet. Other genera are glaphyorhynchus, colodon, and gnathosaurus of H. de Meyer. The T. longirostris (Et. Geoffr.) was found in the kimmeridge strata of Havre and Honfleur, and described by Cuvier in his Ossemens fossiles.

TELESCOPE (Gr. Tŋλe, far, and oxоnew, to view), an optical instrument designed to aid the eye in viewing distant objects, causing them to appear magnified by enlarging the

angle under which they are seen, and at the same time increasing their brightness by collecting into the eye a greater number of rays than would naturally enter it. To this instrument we are indebted for almost every item of our knowledge respecting the physical appearance of the heavenly bodies, while to the navigator, the explorer, and the engineer, it is a powerful and often indispensable auxiliary, either as an instrument of research or when adapted to instruments of observation.-The general construction of the telescope is based upon the well known property possessed by a convex lens or concave mirror, of converging to a focus the rays of light falling upon it from any object, and of forming at that focus an image of the object itself. This image may be rendered visible, as in the camera obscura, by interposing at the focus a white screen, a plate of ground glass, or, still more strikingly, a cloud of light smoke within which the image will appear suspended. But if the rays be allowed to proceed without interruption, and the eye be placed in the axis of the lens or mirror and at the proper distance from the focus, the image will be seen more distinctly than before; and if the focus be nearer to the eye than to the lens, the apparent dimensions of the image will be greater than the apparent dimensions of the object itself. This is the simplest, though not the common form of the telescope. Usually a second lens, of shorter focus than the first, is introduced near the image, the effect of which is to increase still further the apparent magnitude of the object; and thus is constituted the ordinary telescope, which, in its elementary construction, consists of an "object glass" or "object mirror," of as large dimensions as practicable, and an "eye lens," which enables the eye to receive the image under the greatest practicable angle. The object glass is always necessarily convex, and the mirror concave, but the eye glass may be either; if convex, it is placed at the proper distance beyond the focus, and, the rays having crossed, the image then appears inverted; if concave, as in the common opera glass, it is placed within the focus, and objects appear in their natural position. The magnifying power of the instrument is measured by dividing the focal distance of the object glass by that of the eye piece; the illuminating power depends mainly on the size of the object glass.-English writers are fond of alleging that the telescope was certainly known to Roger Bacon and used by Digges before the 17th century, but the first really definite accounts of the invention date from the latter part of the year 1608. Magnifying lenses had long been known, and even the compound microscope had been invented by the Jansens nearly 20 years before this date-a discovery which has somewhat embarrassed the study of the question before us from confusion of the by no means explicit terms with which both instruments are described. But it is now generally conceded that the honor of having made the first telescope belongs to one of two

individuals, Hans Lippersheim, a spectacle maker in Middelburg, and Jacob Adriansz, called also Metius, a native of Alkmaar. The former of these, on Oct. 22, 1608, presented to his government three instruments with which one could see things at a distance," applying at the same time for a "protection" or other equivalent for a patent. Metius made a similar present and a similar application later in the same month, but said that he had manufactured such instruments two years before. It has been frequently stated that Zacharias Jansen also invented the telescope more than a year later; but the evidence adduced only proves, according to Olbers, that he made telescopes which may have been imitated from those of Lippersheim; and this is the more likely as both were spectacle makers in the same city, and it is hardly possible that the public transaction with the latter could have escaped the knowledge of Jansen. The attempt was made by the states-general, it is said, to retain to themselves the knowledge of this invention, whose importance in war was at once perceived by Prince Maurice; but it is also said and believed that the French ambassador soon succeeded in obtaining from them an order for two telescopes for his own government. It is certain that the report of the invention soon spread abroad, and the new and wonderful instruments found their way to London, Paris, and even Venice. But by no person in any city was the idea more eagerly welcomed, or its great importance more quickly recognized, than by Galileo, then visiting at the last named place. He was evidently willing, at a later day, to be thought the second inventor, guided only by an uncertain rumor; but it is reported by some that he actually saw one of the Dutch telescopes, and Huyghens, referring to the matter, declared that the man who could invent the telescope unguided by chance would be more than mortal. Whether seeing the instrument or not, however, his sagacious intellect fully appreciated the great scientific value of the invention; and returning to Padua with some lenses, he immediately began to improve upon what he had seen, if not to experiment independently, under guidance of the mere report, and he soon found a better and more certain result than had been chanced upon by the original inventor. He made a leaden tube, and fitted at one extremity a plano-convex lens for object glass, and at the other a suitable planoconcave for eye piece. This, his first telescope, magnified only three times; he then made another of more than double this power, and soon after, with a magnifying power of 30, the "Tuscan artist" betook himself to the study of the heavens, where his first discoveries excited more wonder than that of the "optic glass" itself. The popular curiosity excited by both was so great, as he himself tells us, that he was compelled night after night, though wearied, to stand by his glass to show its wonderful performances to the curious. But we can scarcely

form a conception of the importance to science of the new invention. The phases of Venus, questioned hitherto, were revealed to sight; the satellites of Jupiter and the oblong shape of Saturn were distinctly seen; the lunar mountains were measured; spots were found upon the sun's disk; the milky way was resolved into stars; and on every side paths were opened for entering upon new and more correct views of the constitution of the universe. In 1609, the same year in which Galileo's telescopes were made, others found their way into England, and were soon sought after with an avidity that was stimulated by the report of Harriot's discoveries. This young astronomer, with zeal and enthusiasm no whit inferior to Galileo's, made drawings of the moon, discovered the satellites of Jupiter, and observed the spots upon the sun. The new "cylinders," as they were called, were soon in general use, and amateurs were greatly delighted with the new aspects of the heavenly bodies, especially of the moon, where they found luminous points "like starres" appearing separated from the main illuminated portion of the new moon, and where, as one expresses himself, "the whole brimme along lookes like unto the description of coasts in the Dutch bookes of voyages." Telescopes were also exposed for sale in Paris in the early part of the same year. It is generally supposed, in the absence of evidence to the contrary, that these first telescopes were all, like Galileo's, made with a concave eye lens, a construction in which, as has been said already, objects appear in their natural position, but with a very limited field of view. Kepler, in 1611, suggested the use of a convex eye lens; but the first actual application of one was made by the capuchin Schyrle de Rheita, who describes it in his work Oculus Enoch et Eliæ (1645). This eye lens gives a much larger field of view, but shows objects inverted. On the other hand, the Galilean telescope possessed the advantage of greater distinctness and brightness than was found in the "astronomical" form. It was imagined by some that a sort of interference of rays took place at the crossing point, and at first sight, and while the true cause of the indistinctness was unknown, the opinion appeared plausible. Even as late as 1776, the elder Herschel thought it worth while to disprove this idea by an actual experiment, devised with his characteristic ingenuity. The true cause The true cause of the advantage of the Galilean form is now known to lie in the partial compensation by the negative eye piece of the aberrations caused by the object glass, the result being in this case the difference, while in the astronomical telescope it is the sum, of the aberrations of the two lenses. Rheita invented also the binocular or double telescope, a construction which frequently recurs afterward, but always as a thing of curiosity rather than of practical utility until in modern days, as the double opera glass or lorgnette, it has become serviceable in reconnoissances, terrestrial and celestial.-The very

first attempts to gain magnifying power and light, by enlarging the object glasses of telescopes, revealed a most unexpected and formidable obstacle. It was found that all objects appeared strongly tinged with prismatic colors. This obstacle remained unexplained until the time of Newton, and unconquered more than half a century longer; and the final victory over it will ever remain as one of the great achievements of the human intellect. But if at the time insurmountable, it did not prove unavoidable, for it was ascertained that by making the focal distance of the object glass very great in proportion to the diameter, the colored fringes could be reduced so as to become practically imperceptible. Enormously long telescopes were therefore constructed, and it was with them that the brilliant discoveries of that day were made. Huyghens used telescopes of his own manufacture, and one of his object glasses, 123 feet in focal length, is still to be seen in the library of the royal society of London. English makers also produced telescopes of nearly equal dimensions, and Auzout in Paris spoke of surpassing all others, but it does not appear whether he succeeded or not. The elder Campani, at Rome, made lenses of from 70 to 136 feet focus, and with these Cassini discovered 4 of the satellites of Saturn, an addition to astronomical knowledge which was thought worthy of commemoration by a medal. Beside the lenses of Campani, some of which are still preserved in Paris, Cassini used also others made by Borelli of 40 and 70 feet, and by Hartzoecker of not less than 250 feet focus. These object glasses were used without any tube, the lens being placed upon a mast, or, as Cassini recommended, at the angle of a tower, and controlled, not without considerable difficulty, by cords leading to the observer at the eye lens.-The source of the inconveniences attending the use of shorter lenses was generally supposed to lie wholly where it did really lie in part, in the imperfect collection of the rays of light, which were at that time believed to be homogeneous, into a simple focus. It was distinctly understood that the rays which passed through a lens near its centre would not be refracted to precisely the same point with those which pass through it near its circumference; that is, there would be what is technically called spherical aberration. This is a true cause, but by no means the whole cause of the indistinctness of images in the telescope. Accordingly, with that belief, it was thought the evil might be remedied by grinding lenses with other surfaces than spherical, and machines were devised by Descartes, by Hevelius of Dantzic, by Du Son of London (who ground deep parabolic concave lenses, with which he asserted that telescopes might be used "with full aperture," and yet show no colors), by Sir Christopher Wren, and others. The main reliance of the astronomer however until near the close of the century was in the aërial telescope, with which, unwieldy though it might be, many

brilliant discoveries were made.-An improvement, of more importance than that of the figuring of lenses, consisted in the modification of the eye piece. By the introduction of more than one convex lens, Rheita had reinverted the image; but this was all the gain that either he or Kepler, who also proposed the same thing, scems to have expected. In fact, there resulted an increase of aberrations which begat distaste of the plan, and it was not until about 1659, when Huyghens invented the combination which still bears his name, that much advantage was gained by multiplying lenses. This eye piece is composed of two convex lenses, whose focal lengths are as 3 to 1, and which are separated from each other by an interval equal to half the sum of these focal lengths; the place of the telescopic image being between the lenses. This arrangement was found to have a remarkable advantage in point of distinctness over the single eye glass, by reason of the apportionment of spherical aberrations between the lenses, and the consequent less amount of injurious effect in the result, while no addition whatever was made to the color of the images formed by the object glass. To this day the "Huyghenian eye piece" remains one of the best combinations for ordinary viewing purposes. Another eye piece, less successful, however, was constructed by Campani with 3 lenses so arranged as to show objects "without any iris or rainbow colors."-In the form to which the refracting telescope had now been brought, it remained full three quarters of a century without further material improvement. But during this interval, by the application of the telescope to instruments of observation, astronomy was continually gaining in the accuracy and extent of knowledge respecting the positions and movements of the heavenly bodies. Morin, professor of mathematics in the college of France, first in 1634 attached a telescope to the moving index of a graduated arc, in order, as he says, "to measure the fixed stars quickly and accurately." He was also the first to gain sight of stars in the daytime. Having, one morning in the early twilight, directed a 14 foot telescope attached to the alidade of a planisphere upon Arcturus, he followed the star until after the sun had risen; and finding that it still continued visible, his joy was so demonstrative that his instrument was displaced and the star lost. He afterward succeeded in following Venus and other planets, as well as several fixed stars, into the daylight. But it was only after the introduction of fixed threads into the field of the telescope, that it became a really useful auxiliary to instruments of measurement. At the present day it seems at first strange that astronomers should have preferred the simple "sights" or pinnules," with which they had always been accustomed to observe, to the far more accurate perception furnished us by the telescope; and yet they, without any means of designating the centre of the field of view, and

with only the feeble optical power at their command, were right in their preference. Even as late as 1673, Hevelius, who had spent a long life in the construction and use of large instruments, as well as telescopes, argued earnestly in favor of the pinnules for observing-not, as stated by Whewell, because it would make all the old observations of no value, but rather from a want of confidence in the new method, which he said had not yet proved itself superior, especially in the case of comets. A controversy upon this question arose between him and Hooke, in consequence of which Halley was requested to visit Dantzic and make actual comparison of the two methods. He did so, when it appeared that Hevelius had acquired such skill in the use of his favorite method, that the difference of their observations seldom exceeded a few seconds, and in no case amounted to so much as a minute! As early as 1641, Gascoigne, an accomplished young English astronomer, had applied fixed threads to the telescope. In a letter to Crabtree he says that he has fitted his sextant "by the help of the cane (tube), two glasses in it, and a thread, so as to be a pleasant instrument." The object he had proposed to himself was the improvement of the lunar theory, and he "doubted not in time to be able to make observations to seconds." He had also at this time invented the wire or filar micrometer, in the details of which it is pleasant to find not merely mechanical ingenuity, but also a true appreciation of the astronomical requirements of such an apparatus; and there is no doubt that, had the inventor lived to make a more extended application of his contrivance, the results would have been of high value. Gascoigne perished untimely at the battle of Marston Moor, and his invention, of which no account had been published, and which does not seem to have been sufficiently appreciated at the time, remained forgotten until nearly 30 years after, when an opportunity for reclamation occurred upon the reinvention of the micrometer by Auzout. It was about the same period that Roemer gave to the telescope one of its most important applications, by attaching to it an axis at right angles to its length, and placing it so as to revolve in the plane of the meridian and shortly afterward Picard in Paris, and Flamsteed at Greenwich, following up this capital idea, commenced a new era in observation. For a more detailed account of this application, see TRANSIT CIRCLE.-Mersenne, in his correspondence with Descartes, had before the year 1639 suggested the practicability of using a concave mirror instead of the principal lens in the telescope; but the idea appears to have been unfavorably received by the latter. In 1663 James Gregory, of Edinburgh, published, in his work entitled Optica Promota, the plan of a reflecting telescope, consisting of a concave mirror, perforated in the centre, by which the rays were to be converged to a focus before it, and after crossing would be received upon a