This Idea was given me by Dr. B. F. at Passy 1. Novemb 1784.

[there is a diagram showing a cross section of the kitchen fireplace & chimney with floor levels indicated] Note the Back of the Kitchen Chimney being of Iron will warm the Room behind it, the folding doors being open allows the heat to pass into the Room & the air Pipe being shut prevents its going away: this is for Winter.—In summer the Doors being shut the heat cannot get into the Room & the slides being drawn out the heat will escape throw the air pipe. the hole at the bottom of the Doors feeds the pipe with Air which rarifies & passes off. The Wooden Pipe supplies the Room with as much cool Air fresh from the bottom of the Cellar.—Room to be warm in winter and cool in summer. [the diagram is labelled:] the Kitchen Fire place & Chimney Cellar. [other notes on the diagram include:] [located behind the fireplace:] an Iron back throw which the heat comes into this Room [behind the flue:] an Air Pipe shut at the Bottom by an Iron slides in Winter but open in Summer. a Wooden Pipe open at each end from the bottom of the Cellar, to the Top of the Room.