PHILOSOPHICAL SOCIETY OP WASHINGTON. 201 



and exhibited the instrument, made by an employe of the U. S. 

 Coast Survey. 



146th Meeting. June 22, 18t8. 



Vice-President Welling in the Chair. 

 Thirty-five members and visitors present. 



Mr. E. B. Elliott made a communication on 



AN adjustment OF THE CARLISLE TABLES OF REVERSIONS AND 



annuities, 



reducing the irregularities by means of equations such that the 

 first and second orders of differences showed no manifest irreg- 

 ularity. 



The subject was discussed by Mr. Woodward and others. 



Mr. B. Alvord made a communication on 



NEW points respecting THE INTERSECTIONS OF CIRCLES AND 

 THE INTERSECTIONS OP SPHERES, 



relating especially to the number of solutions when the question 

 is, "To draw a circle which shall cut each of four given circles 

 at the same angle, said angle being unknown ;" also, "To draw 

 a sphere which shall cut each of four given spheres at the same 

 angle, said angle being unknown," and the number of solutions. 



Mr. Harkness made a communication on 



THE VELOCITY OP LIGHT AND DETERMINATION OP THE SOLAR 

 PARALLAX. 



147th Meeting. October 12, 1878. 



"Yice-President Taylor in the Chair. 

 Thirty-six members and visitors present. 



The election of Mr. Charles Valentine Riley, Entomolo- 

 gist of the Agricultural Department, as a member of the Society, 

 was announced. 



