SLATY CLONGOMERATE. 
141 
lava flow reaching the sea shore and becoming consolidated 
would, in a short time, be worn away by the action of the 
water, and, forming pebbles, be mixed up with the shingle 
already present; the addition of a cementing material would 
soon form a conglomerate, which, as the volcano grew, would 
be covered up either by lava flows or by ejected ashes from 
the crater.” 
This course of events could only follow when the volcano 
was situated near the sea coast or as a volcanic island in 
the seas of that time. If this was the case in our Cliarnwood 
rocks the upheaval and depression required could be 
explained. If, on the other hand, this conglomerate was 
deposited on the shores of a lake, bounded or surrounded by 
volcanoes, we should expect to find the pebbles composed 
almost entirely of the fragments ejected from them, together 
with fragments of ashy rocks that would fall from their sides. 
Although the majority of the pebbles cannot be correlated 
with any known exposure of the Cliarnwood rocks, it is very 
probable that the parent rocks have been removed by 
denudation. The presence of the small crystals of quartz in 
the majority of them would seem to indicate that the rock of 
which they are composed cooled slowly, and, from its 
appearance, it is probably a volcanic lava ; so that the 
supposition of contemporaneous denudation is somewhat 
strengthened, but whether formed on a lake or seashore can¬ 
not be said. The lake theory is, however, the most probable, 
as there are no indications of any other than shallow water 
deposits in the whole series of the Cliarnwood rocks, and 
with regard to the depression and upheaval required, the 
unstableness of level of volcanic districts is well known. 
METEOBOLOGICAL NOTES.— March, 1884. 
Temperature was low at tlie commencement of the month, and the 
sky generally overcast or cloudy. There was a considerable fall of rain 
and snow (0*64in.) on the 3rd. A sudden rise of the barometer on the 
4th was accompanied by temporary improvement. From the 6th the 
barometer fell somewhat rapidly, reaching its lowest point for the 
month (29T32in.) on the 10th. From thence it rose rapidly to the 
14th, and a short spell of summer-like weather continued till the 
19th. The highest temperatures were recorded on the 16th, viz., 
69T°, at Loughborough ; 68-4°, at Hodsock ; 66-8°, at Coston Rectory ; 
and 66T°, at Strelley. These values are unusually high for the month 
of March, but are in no degree an indication of an early summer, as 
