TRANSACTIONS (SERIES II.). 
Voy. I.—Parts 1-25.—November, 1877, to September, 1883. 
Voy, I1.—Parts 1-2.—August, 1879, to April, 1882. 
Voy,. ILI.—Parts 1-14.—September, 1883, to November, 1887. 
Vor. IV.—Parts 1-14.—April, 1888, to November, 1892. 
Vou. V.—Parts 1-13.—May, 1893, to July, 1896. 
Vou. VI.—Parts 1-16.—February, 1896, to August, 1898. 
VOLUME VII. 
Parr 
1. A Determination of the Wave-lengths of the Principal Lines in the Spectrum of Gallium, 
showing their Identity with Two Lines in the Solar Spectrum. By W. N. Harrtey, 
F.r.s., and Hue Ramaes, A.r.c.sc.1. Plate I. (August, 1898.) Is. 
2. Radiating Phenomena in a Strong Magnetic Field. Part I1.—Magnetic Perturbations of 
the Spectral Lines. By Tuomas Presron, M.A., D.sc., F.R.S. (June, 1899.) Is. 
3. An Hstimate of the Geological Age of the Harth. By J. Joy, M.A., B.A.t., D.sc., F.R.S., 
F.G.S., M.R.1.A., Honorary Secretary of the Royal Dublin Society; Professor of Geology 
and Mineralogy in the University of Dublin. (November, 1899.) 1s. 64. 
