236 
Analyses of Books. [April • 
through the fifteen representative plants here described will pos- 
sess an amount of knowledge such as he could never acquire 
from books alone, or from the mere cursory and superficial 
examination of specimens. It is therefore at once a duty and a 
pleasure to recommend this little volume. 
Dimensions of the Fixed Stars. With especial reference to 
Binaries and Variables of the Algol Type. By Edward C. 
Pickering. Cambridge (U.S.): J. Wilson and Son. 
The author proposes to give a full trial to the method taken in 
the case of satellites and small planets, — in other words, to deduce 
their dimensions from the amount and character of their light. 
As a result of this method, he gives for the two components of 
a Centauri the respective magnitudes of 1-82 and 0*46 times that 
of the sun. 
As regards variable stars of the Algol type, where a maximum 
and minimum of brightness succeed each other periodically, the 
author discusses several theories, and favours the supposition 
that the variation in light is due to the interposition of a non- 
luminous satellite. 
This memoir is reprinted from the “ Proceedings of the Ame- 
rican Academy of Arts and Sciences,” vol. xvi. 
The Journal of the Royal Historical and Archaeological Associa - 
tion of Ireland. Vol. V. Fourth Series. No. 41. 
This number contains an account of a megalithic structure at 
Mongnacool Lower, County Wicklow, locally known as the 
Fairy House. No traces of urns have been found, nor is there 
any appearance as if the ground had been disturbed by treasure- 
seekers. There is also a notice of a flint knife and an ornamented 
bronze celt found in the Count)' Tyrone, a region where the 
manufacture of such implements appears to have been extensively 
carried on. About five years ago a large collection of bronze 
arms and tools, all damaged, was found hidden beneath a huge 
block of stone in Bo Island, in Lower Loch Erne. 
