Last night, the wind having changed suddenly to the N. West it was exceedingly cold for a short time,—and this morning the condensed vapor was found to have dropped upon the decks in 3 or 4 places in the Hall of Representatives, but in one place exactly over one of the decks, a quantity fell equal to about a Wine Glass full. On going onto the roof I found the Cause of this difference. In puttying down the Glass I ordered a space of about an inch deep to be left at A above the putty in which the Water might lodge. [IMAGE] In all the other lights from which no water dropped this space was full of water & in most it had run down into the pannel, where it remained. But in that particular case the space was not quite as deep as elsewhere, & it had therefore overflown, & when once a drop falls, all the rest must follow. No baize can possibly be put under the Glass, because the Glass is solidly puttied onto the lower frame & screwed down. When the frost begins I fear still worse consequences, which I know not how to prevent. I am with the highest respect Yrs. faithfully