16 H. A. LENEHAN. 
the image by three and eight times, respectively. Alto- 
gether 44 plates were exposed, eleven of these during 
totality. A negative exposed two minutes before totality, 
shows a reversed image, due to over-exposure, and a 
silhouette of the corona. | 
Attention has recently been given during total eclipses 
to the question of the existence of any planet or planets 
nearer to the sun than Mercury. Such planets, if so situ- 
ated, would be illuminated by a very intense solar light, 
if only one-half or one-quarter of the diameter of Mercury. 
It might be possible that such planet could be hidden in 
some eclipses of the sun or moon, or its light be over- 
powered by the corona, if our line of sight to it pass very 
near the sun; but, if so, it should be visible in other 
eclipses when in other parts of its orbit ; up to the present 
no such planet has been detected. In the eclipse of 
May 18th, 1901, the remarkably long duration of totality 
(65 minutes) was very favourable for these observations. 
Unfortunately for some time to come there will not be so 
good an opportunity to observe. In 1907, it would involve 
a trip to Turkestan or Mongolia; in 1908, or 1911, to the 
Pacific, and in 1912, when the very rare occurrence of 
two total eclipses (only six months apart) will take place 
in South America and the Spanish peninsula; these will be 
of short duration. In 1919 an eclipse of long totality will 
be visible in Brazil and central Africa. 
Changes on the Moon’s surface.—FYrom time to time, 
astronomers who make special studies of the lunar surface, 
have intimated their belief that changes of various kinds 
may be occurring on the surface of our satellite. Professor 
W. H. Pickering, as the result of a long series of speciay 
observations in Peru, Jamaica, and California, believes 
that physical changes do occur, and that they may 
be classified under three heads, due respectively to 
