616 transactions of the american institute. 



Orbits of Binary Stars. 



Prof. Kirkwood, in Silliman's Journal for March, directs attention to the 

 fact that the orbits of binary stars, so far as observed, are much more 

 elliptical than those of the planets. Of the whole number of apparently 

 double stars known to us, about 6,0()0, no less than 650 have changed their 

 relative position. The almost circular path of planets around the sun and 

 the extremely elliptic motions of the self-luminous stars are both accounted 

 for by the theory of Laplace, as explained by Prof. K. For if a mass of 

 nebulous matter in which the process of condensation has commenced, has 

 a very slow rotation, and if, instead of a single center of attracticm, two 

 distinct nuclei be formed, the consequence may be its complete separation 

 into two bodies, while the rotation is yet so slow that the centrifugal force, 

 as compared with the centripetal, is too feeble to produce a nearly circular 

 motion. While, therefore, orbits of small eccentricity must characterize 

 planets formed from the abandoned equatorial rings of a condensing nebula, 

 orbit; highly elliptical maybe regarded as the probable consequence of a 

 separation in the earlier stages of its physical history. 



Watson's Comet. 



Mr. "Watson, of ^Vnn Arbor observatory, communicates to Silliman's 

 Journal the elements of the orbit of the new comet discovered by him on 

 the 9th of January, which almost exactly resemble those of the comet of 

 1810. This comet was barely visible to the naked eye in the latter part of 

 January, and in a comet seeker exhibited a tail about two degrees in 

 length. 



Progress of the World's Telegraph. 



The Russian telegraph line in the direction of America is now complete 

 from Omsk to Irkutzk. Dispatches from St, Petersburg reach Irkutzk, a 

 distance of about 5,750 versts, in less than one day. Letters transported 

 between these places are twenty- four days on the route. The Russian verst 

 being equal to 3,501 American feet, the whole length of the line completed 

 is 3,815 miles. 



Steel Rails. 



From experiments on the London and North Western railway, it is con- 

 cluded that one pair of steel rails will last as long as ten pair of iron rails, 

 subjected to the same amount of wear. 



The Great Trunk Railway. 



A project has been started to construct a railway underground from the 

 Battery to the northern extremity of Manhattan Island. The act to autho- 

 rize a company for this purpose, with a capital of $5,000,000, is now before 

 the legislature. It names as corporators some of the most prominent and 

 wealthy gentlemen of New York. The route has been pronounced feasible 

 by competent engineers. A similar underground railway in London, ex- 

 tending five miles, is said to be a success. 



Without entering into the details of this project for tunneling New York, 

 which follows the trial and abandonment of a short tunuel_, in the city of 



