ROYAL DUBLIN SOCIETY. 
HUNDRED AND FORTY-SEVENTH SESSION, 1877-78. 
MINUTES OF PROCEEDINGS, 
Monpay EVENING, FEBRUARY 18TH, 1878. 
Section I.—Physical and Experimental Sciences. 
(With which the “ Dublin Scientific Club” is associated.) 
Rev. RICHARD TOWNSEND, F.T.C.D., F.R.S., in the Chair. 
The following Communications were laid before the Section:— 
The Right Hon. The Eart of Rosss, Fr.z.s.—‘ Observations of Nebule, 
made with the six-foot and the three-foot reflectors at Parsonstown, 
from the time of their erection to the end of the year 1877.” 
(Ordered for publication in the Transactions, Vol. I.) 
J. E. L. Dreyer, u.a.—“ Notes on the Physical Appearance of the 
Planet Mars, as seen with the three-foot reflector at Parsonstown, 
during the opposition of 1877, accompanied by drawings of the Planet.” 
(Transactions, Vol. I., Part VI.) 
Howarp Grup, M.E., F.R.A.S.—‘‘A new form of Contact Breaker.” 
(Proceedings, Vol. II., Part I.) 
G. JoHNSTONE STONEY, M.A., F.R.S., Hon. Sec.—“ The Mechanical Theory 
of Crookes’s Force.” 
(Transactions, Vol. I., Part IV.) 
Professor Barrett exhibited a series of Acoustic Figures produced by 
the Voice. 
Section II.—Natural Sciences. 
(With which the “ Royal Geological Society of Ireland” 
is associated.) 
Rey. MAXWELL H. CLoSsg, M.A., in the Chair. 
The following Communications were laid before the Section :— 
Anniversary Address to the Royal Geological Society of Ireland, 
delivered by the President, Rev. MaxweExu Coss, M.A. 
' (Proceedings, Vol. II., Part I.) 
Rey. Dr. HaucurTon, F.R.s.—“ On the Theoretical and Actual Distribu- 
tion of Sun-heat on the Surface of the Earth, from which is inferred 
the absolute Radiation of Heat into Space from the Earth ; together 
with Observations on the Work done by the Sun-heat not accounted 
for.” 
(Proceedings, Vol. II., Part I.) 
R.D.S, MINUTES. 
