The Bridgeport times and evening farmer., 1919-03-12

Om bia University observatory StaIL.) April this year Is a particularly fine month for observation of the Earth's fellow planets. Our map shows the positions of Jupiter and Saturn, which are easily distinguish able, and also that of Neptune, which, to our regret, is invisible to the naked eye. But, brighter than any of these is the beautiful evening star, which we have all noticed in the western sky after sunset, gleamtng in solitude on the blue background long before any of the neIghboring heavenly lights are visible. This is Venus, and Venus Is the brightest of the regular celestial objects, next 10 the Sun and the Moon.
 AS this planet sets just before the time of the map, 1t does not find q. place on 1t, but one needs the aid of no map for its recognition. If the sky in the West in cloudless, all you have to do is to look in that direction, even a half hour before sunset. Next month, Venus will appear on the map, because 1t is at the present moving eastward from the Sun and thus in creasing the time interval between it's setting and that of the Sun. Mars Is too near the Sun for good observa.- ton and will change from an evening to a morning star in the course or the month.
 Neptune, the Invisible,
 The ancients did not know of Nep tunes existence, for their astronomy ,-yas hampered by the lack of optical Instruments. They had instruments with which they made measurenle ents of position, but with peep-sights only. Neptune Is the outermost planet of the Suns family, the one most remote from us and the Sun, so that, in spite of It's huge bulk, the eye unaided can not perceive 1t
 Perhaps the most interesting thin g about the planet 1s the circumstance of its discovery. Its inner neighbor, Uranus, was discovered by Sir William HerscheI in 17ss and was Identified as planet by Lexell, a mathematical astronomer, for Herschel at first thought 1t was a comet. Immediately, extremely careful and numerous op- eervations of Uranus were taken, and 1t was discovered that it's positions did not quite fit any orbit which could be worked out for 1t. It certainly was a planet, but 1t seemed to run cnn- trary to the law of gravitatior, which is a consideration no astronomer can for a moment entertain.
 Another planet, still more remote than | Tdhu5s COulu nave buCll d Olh- turbing effect upon 1t, but no such planet was known. Easing their cal culations on this possibility, two men independently worked out the prob able position of 8 disturbing planet if such existed. One was an English man, Adams by name, and the other a Frenchman, Leverrier. Adams sent his results to the Astronomer Royal at Greenwich, with a request that he search for the unknown; but nothing was done. Leverrier sent his data tC Galle at Berlin-the date was 1S46- who took the matter up with enthu. siasm and acted upon 1t the very first night, finding the new planet within a short distance of the predicted posi-. ton. Had the Greenwich astronomer acted on Adams request, he too could have found Neptune, for Adams cal culations were also correct. Both men share the honor.
 Because of Neptune's distance, very little more than It's dimensions anc distance is known about 1t. There 1: one satellite, about as big as oul moon. which revo1ves about the planet in the opposite direction from that taken by the moon and mos other satellites in revolving abou their respective planets.
 Neptune's diameter Is 35,O00 mile! Cthe earth's is s,00O) and 1t contains seventeen times as much matter a! the earth, though it's average density is only slightly more than that of wa ter. Its distance from the Sun is 2, 792.OO0,O00 miles, which Is 3,00t times the earth's distance from tn sun, and its year Is equal to 165 ter restriaI years. In fact, its distance is so great that it receives only on ntne-hundredth as much heat iron the the Sun as we, and the mid-da, Hlumfnat tion on Neptune Is about 65 times our full moon light, whereas on the earth, sunlight is probabl. equal to the light from half a million full moons. There seems to be good sized atmosphere. which i rich in water vapor,- and some da Neptune will be like the earth is to day. while the earth by then may b as dead as the moon.
 The Stars and Cancellations
 The east now holds that particu Iariy fine section of the heaven which contains the groups of Orior Taurus Auriga, the Twins and tn two dogs No less than seven, oJ oE a total of twenty, first-magnitud stars are found here. Those ar Albebaran. Capella, Rigel, Betel geuze, Pollux, Procyon and Sirius Pn names of great importance.
 In addition we have here tn NFgeades, the Hyades, the famous Be of Orion and the wonderful Orio Nebula- These are winter constella tions, and with the coming of Sum mer we shall lose them; in fact, Orio and Taurus will no longer appear o our map until next winter, thougl of course, they may still for som weeks be observed before the hot of the map.
 fCapeIla is rather an exception this; because 1t lies so close to tn north celestial pole that it is aboy the horizon and visible to us th sfeater part of the year. Regulus
 just about on the meridian at ma time and can be easily recognized b. .-nfrra thA nrnximitY of the nlanet s.