73 
Ordinary Meeting, January 7th, 1868. 
Edward Schunck, Ph.D., F.R.S., &c., President, in the 
Chair, 
“Variable Spot on the Moons Surface,” by W. R. Birt, 
F.R.A.S., communicated by J. Baxendell, F.R.A.S. 
The interest attaching to the phenomena presented by 
the lunar spot Linne is my apology for communicating a 
few observations on another spot which exhibits similar 
phenomena. It will be seen that both spots manifest phe- 
nomena which appear to be referrable to the presence of a 
covering by which the craters are at times concealed. We 
are not cognisant of any agency such as libration, angle of 
illumination, or variation of distance which affects the forms 
and appearances of lunar objects, being capable of rendering 
a crater invisible while its place is occupied by a white 
cloud-like spot of light; nor are any of these agencies 
capable of rendering an object on the moon’s surface indis- 
tinct while others in its immediate neighbourhood are 
exceedingly sharp and well defined. With the hope of 
directing the attention of astronomers to this curious class 
of lunar objects, may I be permitted to lay the following 
observations before the Society ? They have been made 
principally by the Rev. W. 0. Williams of Pwllheli, who 
has undertaken the examination of a zone on the moon’s 
surface of 2° of latitude, viz. from 4° to 6° south. 
Proceedings— Lit. & Phil. Society.-— Yol. YII.— No. 7— Session 1867-8. 
