Notices respecting New Books. 145 



negatively electrified and deflection about \ centim. towards 

 iron, the case was connected with the hydrogen-sulphide bottle, 

 and sulphuric acid poured in to generate the gas. At 2J- 

 minutes afterwards the lead-paper began to darken at edge ; 

 and in half a minute more the needle crossed the zero-line and 

 turned towards the copper half of ring — deflection about \ 

 centim. The needle was then connected with positive con- 

 ductor and immediately turned towards iron ; connected again 

 to negative it turned towards copper ; and so on, till in about 

 10 minutes after admitting the gas the deflections became un- 

 decided, the copper having become covered with sulphide, 

 which has no affinity for sulphur. 



Edenderry House, Belfast, 

 January 1878. 



XX. Notices respecting New Boohs. 



Astronomical Observations made at the Royal Observatory, Edinburgh, 

 Vol. XIV., for 1870-1877. By Piazzi S^tyth, F.B.S.E. Sfc. 

 Published by order of Her Majesty's Government. Edinburgh : 

 JNeill and Co., 1877. 



TN this volume Professor Smyth has given his attention to a most 

 -■- important feature of Sidereal Astronomy, viz. " Stellar Proper 

 Motions." At present we know but little either of the distribution 

 of the stars in space or of the directions in which they are moving. 

 Proctor has shown that groups of stars separated, as seen by the 

 unassisted eye, many degrees from each other, possess a community 

 of motion, the logical inference being that they are in some way 

 connected. The spectroscope reveals to us the fact that many stars 

 are receding from us in the line of sight, and that others are ap- 

 proaching us in the same line. Proctor's deduction of " Star 

 Drift " is based, if we mistake not, on the Proper "Motions as given 

 in various catalogues which he found necessary to study in con- 

 structing his star-maps ; but neither the present recorded Proper 

 Motions nor the recorded motions in the line of sight give us any 

 information as yet as to the distribution of the stars in space ; and 

 if Professor Smyth's suggestion be carried out, of filling up the 

 lacunae purposely left in his catalogue for the reception of obser- 

 vations of II. A. and X.P.D. from other sources to which he has not- 

 had access, it is extremely probable that many corrections may be 

 made to the numerical values of Proper Motions now on record. 

 Whether the Astronomer Royal for Scotland has succeeded in truly 

 correcting the values on record or not, he has at all events drawn 

 the attention of astronomers to the subject, and that in a May which 

 cannot fail of contributing to its advancement. 



It is considered, by astronomers competent to give expression to 

 Phil. Mag. S. 5. Vol. 6. No. 35. Aug. 1878, L 



