The Term ‘Hemera’

and is daily carried into the lake, whose water has thus become turbid and greenish in colour. The rock excavated along the copper veins is of a greenish colour, as may be seen by looking at the tips from the adit-levels. This change of colour in Llydaw explains the colour of Glaslyn, about the cause of which there has hitherto been some doubt. For it cannot now be doubted that Glaslyn owes its green colour to the detritus of green rock washed into it from the adit-levels of the mines. J. R. DAKTNS. P.S.—I should say that the mines are situated immediately above Glaslyn.