Rensselaer Republican, Volume 12, Number 37, Rensselaer, Jasper County, 4 June 1880 — Secular Acceleration of the Moon. [ARTICLE]

Secular Acceleration of the Moon.

Sir George Airy, who has been tor several years engagtp In a new method of treating the lunar theory, has finished labors, and laid the resalt before the royal astronomical society. The value deduced lor the secular acceleration of the moon’s mean motion is 10 min .1477, and it is remarked that this numerical value is founded on the assumed numerical value of the solar parallax (8 sec .91)—depending,' in fact, on the inverse cube of the parallax. If, for instance, the parallax be diminished-by l-60lh part, the accclera tie* will be diminished by l-20th. In stating this result, the Astronomer Royal said: “I think that this is the toughest question that I have ever had in my' life. It has occupied me, in one shape or another, for many years—some, times attacking it, sometimes repelled by it, and sometimes adhering to it for months together. It is the most slippery thing I have laid my, haads,9Ron; but I have got a grasp upon ft it last, and I have toot the feast doubt of the perfect accuracy of it. I need not sgy that the matter in which I have been engaged is s matter ot great importance, more especially in distant chronology. The total solar eclipses of former times depend entirely upon this small quantity, and I think that in this in -estlgation, which has cost me so much pains, I nave worthily bestowed time and -trouble to give a little certainty to that point” With reference to this secular acceleration, Sir George Airy writes to The Oburoatory: “In the moon’s orbit, 1 sec—--6,000 feet very nearly. In a century, therefore', the moon is accelerated 00,000 feet. In the first year (from the epoch) the acceleration is 6 feet; in the second year 18 feet additional, and so on. This is additive to the computed longitude whether before or after the epoch. In « century the moon’s distance is changed by 60,000-8,400 feet, or 7.14 ft; in one year Uis changed by 0.0714 .of s loot, or Jess than an inch. This change proceeds unifenaly.”

Lucy's Gelatins Puddekg.—Half box gelatine deeeolved in a large half pint boiling hot water; when cold, stir in two teacups of sugar, the juice of three lemons, the whites of four eggs beaten previously to a stiff froth. Put this in a mould to growstiff, and with the yolks of these four eggs and a quart of mtfk make a boiled custard, flavor it with vanilla, and tehen this and the pudding age coid serve on this same’ dish, pouring the custard round the pudding. It is a very flood and handsome dish for desert. ’ ~'r ,7**: - Joe Jefferson stopped acting for the season at Toronto, Saturday night.