Show ON JIT y aar PROF ORSON T LECT I 1 U RE el EVENTS I 1 the planet uranus replis around the sun un at the mean distance oi of 89 of miles the circumference of its 0 of miles A steam carria aei moving at the rate of 20 miles an hour without intermission would require 65 8 years to comp fet the circuit the planet moves boain ir k talis L orbit at aerate doriL tp of about miles mile every hour hopr accorn dirig the journey in in mean solar dayson day soi 84 years the diameter ot or ts planet is s miles its circumference air miles whether it I 1 axis has not t been ascertained has a rotation ufern by observation 1 14 l lt it is ls extremely probable from 1 eions that it has a rotation from theoretical cc isiom west to east cast fik other planets it is also probable that the w ped of its r rotation is 8 about oa 01 9 hours and 30 minute or nearis y the same as that of f ju pa p 1 ter and sata this s planet is too far kom from us to t 0 discover upon pa its surface stace under der the present the telescope w and therefore observe observation a power has n been een able B to 1 detect a rotation the b br of f uranus is over 81 times greater thin than the carta cart 1 ll it is ls only about 15 23 2 3 heavier tha than n the earl ear therefore its density is about the same as that water ar bodies will weigh a little less on the axce of brantis than at the surface of the earth that is a body weighing one pound here w woi d if transported to that planet weigh only 13 1 bances ances fhe inclination of the orbit to the plane of f the elliptic is its deviation from the ecliptic therefore never much exceeds 34 3 4 of a degree uranus was discovered by sir wm herschel on the of march 1781 for more than a century previous to this period astronomers conjectured that there must be some planetary body beyond saturn in consequence of the disturbances manifested in the deviations of saturn and jupiter in their elliptic orbits this conjecture was accidentally confirmed by bv herschel while making a minute I 1 survey of the heavens ile he at first supposed it to be a comet but astronomers soon determined that its orbit was wa nearly neaily circular and unlike a comet no tail or nebulous appearance could be detected every doubt was soon removed and this body was determined to be one of the great planets of our system uranus is accompanied by six satellites none but the most powerful telescopes are capable of perceiving these minute bodies two of these are more conspicuous than the others and their periodic times and distances from the planet have been determined ter tet mined with considerable accuracy the existence of the other four rested solely on the observations of sir wm herschel until the year 1847 when mr lassell and by independent observations ions re detected one more the former of these gentlemen continued his observe observations he upon it from the of Sepi Se ember until the ath of november and the latter from the esth of october until the of 1847 this was found to be interior to the two larger ones mr lassell also re observed another anoche r in intermediate te rine diate between the larger ones the other two if they should ever be re rediscovered discovered will probably be found to revolve in orbits exterior to these the first or the one nearest to the planet is a supposed 1 U p to have a period of about 4 days the second is known to have a period aronno around the planet in ad its iti distance from t the e centre of the primary is miles the distance of the next is supposed to be miles its supposed period lod the fourth revolves around the planet in lah am 1269 its distance is miles the fifth is supposed to perform its revolution in ah at the distance of ft miles the sixth is supposed to accomplish its revolution in at the distance of miles one of the most remarkable remor kable and unexpected peculiarities I 1 is exhibited by the positions of the orbits of these satellites contrary to the whole analogy of all the other planetary bodies of the solar system the planes of their orbits are nearly perpendicular to the ecliptic that is they are inclined to the ecliptic at an angle of no less lhnn and what is still more remarkable they move in these orbits in a setrog retrograde rade direction that is when their positions are projected upon the plane of the ecliptic instead of advancing from west went to east in in the order of the sig signa they move in a contrary direction namely from frona east st to west which is contrary to the direction dire acton of the motions of any other planet or satellite in the whole system the position of these orbits and the retrograde motions of these satellites are probably the results of some interference with the original positions s and movements by causes which at present ar are unknown neptune the discovery of the planet neptune may be ranked among the greatest discoveries that were ever unfolded in the history of astronomy not so much in regard to its f future bearings upon that great science science i as in relation to the curious and roost wonderful manner in which the discovery was made in exploring the heavens in search of new planets the telescope alone seems to have been the grand instrument of research some faint analogies it is Is true have guided the instrumental examinations to certain regions of the heavens in prefer preference enre to others for instance all the older planets were known to revolve in orbits not much inclined to the ecliptic being included within a narrow zone encircling the heavens about lad in breadth callad the zodiac analogy would naturally lead astronomers to regions in in or near this zorie zone as the most likely place for discovering covering din planetary bodies but having arrived in the neighborhood of this zone analogy no longer ceryes serves as a guide and the astronomer has hitherto launched forth into the unknown abyss to be wafted wafred by the minds w ands of fortune perhaps to some new planet but far more mere frequently he returns disappointed and grieved his voyage having been unsuccessful these have been the difficulties and uncertainties which have attended the explorations of the heavens until within a very few years past but bul the period has at length arrived when the mind of 0 man has reasoned its way through the dark clouds of uncertainty has bas soared aloft among the vast vast oceans of telescopic stars and has pointed out almost the exact position of nn an unknown world it would seem almost impossible for the human mind though guided by the most powerful mathematical analysis to point out the direction define the dis etrace out the orbit and weigh the mass of an unknown planet so remote as to be imperceptible to the naked eye yet this has been attempted and the result has brou brought glit to light another great orb of our system which has rolled its ample rounds for ages unk unknown it maybe may be asked how waz was this grand problem solved we reply that it would be impossible to convey a clear allea of the profound and intricate apa analysis lydis employed for its solution to a popular assembly unless they were prepared by a previous knowledge of the higher mathematics we will venture to make inake a few remarks upon tip on this recondite subject since the days of newton it bug ha been known that each planet gravitates towards every other planet in the system with a certain force depending on the distance and quantity of ef matter As the planets revolve in their orbits their distances and directions from each other are constantly varying consequently they must be continually acted upon by variable forces tending to uree them from froin the paths which they would pursue if acted upon by one central f force orce the planetary orbits are ellipses ellipse a when considered in reference to the force deflecting them towards the sun they are constantly deviating from these elliptic paths by af forces ore urging them towards other bodies in in the sy system steni these deviations are called planetary perturbations and can be calculated when the direction distance and mass of the perturbing body is known the perturbations of uranus towards saturn and jupiter were calculated for every point throughout its entire path so BO that the form of its path as depending upon its deflections towards these two bodies ies and the sun were known but by carefully watching ehing the tha progress of uranus it was soon ascertained that it deviated from its calculated orbit both in di recon and velocity the disturbing cause w was s unknown it could not be the influence of the minor planets pla et situated within the orbit of jupiter 0 khoh for they were altogether too small to occasion occasion the observed perturbations various causes were conjectured by the astronomical world to aap account u nt for the deviations of uranus gf some supposed that the law ot of gravitation had in in some small degree changed its nature others supposed that the he planet was perhaps influenced by a comet which might be traversing those distant regions all seemed to jo be uncertainty until two young ge geometers ometery mr adams of cambridge england and leverrier Le verner of france conceived the idea unknown to each other of determining by analytical investigations the direction distance and amount of the perturbing body from the amount of perturbations exercised upon uranus tins this is ic a problem from which any but the most profound mathematicians would have shrunk is as being far beyond the pale of human intellect but these two mathematicians beheld the light glimmering from afar they therefore labored labore d and toiled on with the most untiring perseverance removing obstacle after obstacle ascending highie and yet higher in in their analytical investigations until they gained an ele aaion from which by the eye of reason they could see as yet an unseen world rolling in in its mighty orbit nearly as far beyond uranus as itis it is from the sun having satisfied themselves not only of the existence of the unknown world v orld but of the bartic lar region of the heavens where it existed they an bounced the results of the their ir leverrier Le verner wrote to his friend lr dr galle gale of berlin berhn requesting him to direct his telescope to the point in in the heavens which mathematical reasoning had revealed as the one containing the alio unknown bod body y the first evening after the reception of this communication dr galle directed his telescope to the place pointed out when he at once perceived a star of the eighth magnitude which by a reference to a map he found to be a stranger in that region th alie next evening the star had actually moved from its place with a velocity accordant with the computations of leverrier Le verner the unknown world was found the theory of the french geometer was demonstrated by actual discovery and the whole of the learned wa world ald were astounded at the penetrating judgment and giant intellect of the men who could by analytical reasoning alone rescue a world from the depths of space and assign it a definite orbit orbia among the known orbs arbs of our system I 1 independent of the applause of men how satis factory and plea pleasant sapt must be the feelings of a great and good man when he has been made the instrument me ut of some great and grand discovery when lie knows that his persevering industry and labor have put him in in possession of knowledge and power to open the sublime mysteries of creation and bring to light bilings which have gl slumbered for ages unknown this ever memorable discovery took place or was confirmed on the of september 1846 the actual place of the planet was found to be only of a degree from the computed place assigned by by leve deverner Le verner r rier and only froni from the place computed by mr adams coth both of whom were in m entire ignorance of each other s calculations after the discovery of this distant planet many astronomers bent all their efforts tp to ascertain its distance period form of its orbit orbi tAc ac all of which are called calle d its elements it was soon learned that the planet was seen on I 1 oth of may 1795 and en on the catalogues cataloguer catal as a fixed star from thi this is discovery astronomers were enabled to calculate its ele elements menti with a very great degree of precision tt it revolves around its orbit at the vast dista distance uce of of miles in in a period of no less than chho 71 mean solar days or a little over 12 1 2 of our years this distance is is so great that a cannon ball flying fl ing at the rate of miles per hour would require years to accomplish the journey A steam carriage traveling 20 miles per hour woi would uld be years in in going the distance and to tra verse the whole v hole circumference of its orbit would take lake upwards of I 1 years even light itself would require 4 hours 7 12 1 2 minutes to come from that body to us the diameter of neptune is miles it its bulk therefore is 12 1 2 times greater than the I 1 earth that is I 1 3 12 1 2 globes of the size of the earth if into one would form firm a globe of the size of neptune the density of this planet is in about 17 1 7 of that of the earth that is 7 globes of the size of the earth composed of the materials of which neptune consists would weigh as heavy as the earth therefore the materials which enter into the composition of neptune are only about 57 5 7 as heavy as water and the whole of that planet though 12 1 2 times larger than the earth will only weigh about 20 2012 12 1 2 times more one pound of terrestrial matter transported to the sur surface f ace of neptune will only weigh 12 ounces and 2 drachms drachma drach ms or a little over 34 3 4 of a pound A clock pendulum that will make oscillations at the surface of the earth if carried to the surface of neptune would only make 87 oscillations in the same time bodies will fall near the surface of that planet only 12 f feet ee and I 1 inch in a second where as on the earth they will fall in the same time 16 feet and I 1 inch this planets orbit is inclined to the ecliptic at an angle of I 1 deg it seems to be a characteristic te ristie of all the larger to revolve in orbits but little inclined to each other or to the ecliptic though neptune is too far from us to dete determine by observation whether it has a motion or not yet f from rom analogy and other theoretical considerations erat ions it is quite probable that itT it rotates upon an axis from west to east the same as the ahr ahree e large arge planets next interior to it and it is presumed in about the same period how many satellites attend neptune is as yet unknown one only has haa been certainly observed it was first discovered by mr casselli lassell Las selli oi on july ath 1847 since which time it has been observed by many other astronomers its orbit is inclined to the ecliptic at an angle of but bat whether its i motions in this orbit be direct or retrograde is not yet fully determined its approximate period is 5 days auh and its distance from the centre of the planet is about miles it is from the period and distance of this satellite that the comparative para tive mass of neptune has been computed with a tolerable degree of accuracy though it will hereafter probably undergo some modification fion as observation shall become more perfect from bodes law of planetary distances it might have been expected that the planet neptune should be placed at about double the distance of uranus from the sun but this is found not to be the case bodes law although verified in the case of all the other planets and even among the systems of satellites el lites fails by some six or seven hundred millions of miles in the distance of the new orb this law of planetary distances seems seem sto to be foun ded upon no necessity at least no causes or reasons can be assigned why thi this singular relation of distances should have existed in in so many instances and it is rather |