Q. _Why is the DRAUGHT of a LONG FLUE greater than that of a short one?_ A. Because the _higher_ smoke ascends, the _faster_ it goes; (as a stone falls faster and faster, the nearer it approaches to the earth): if, therefore, a funnel be _long_, the smoke acquires great _velocity_, and the _draught_ is great. Q. _If a CHIMNEY be TOO SHORT, and cannot be lengthened, what is the best REMEDY to prevent smoking?_ A. To _contract the opening of the chimney_ contiguous to the stove. Q. _Why will a_ SMALLER OPENING _against the stove_ PREVENT _the_ SMOKING? A. As all the air (which enters the chimney) _must pass near the fire_, it will become _greatly heated_, and _rise rapidly_ through the funnel; and this _increase of heat_ will compensate for the _shortness of the flue_. Q. _Why will a_ ROOM SMOKE, _if there be_ TWO FIRES _in it?_ A. Because the _fiercer_ fire will exhaust the most air; and draw from the _smaller_ one, to supply its demand. Q. _Why will a chimney_ SMOKE _if there be a_ FIRE _in_ TWO ROOMS _communicating with each other?_ A. Whenever the _door_ between the two rooms _is opened_, air will rush from the chimney of the _inferior_ fire, to supply the _other_; and _both_ rooms will be filled with smoke. Q. _What is the_ REMEDY _in this case?_ A. Let a tube be carried from the hearth of each stove, into the external air; and then _each_ fire will be so _well_ supplied, that neither will need to borrow from the other. Q. _Why do VESTRY CHIMNEYS so often SMOKE?_ A. Because the wind (striking against the steeple) _is reflected back_; and tumbles down the vestry chimney, forcing the smoke _into the room_. Q. _WHAT WINDS make vestry chimneys smoke?_ A. Those from the north-east or south-east; according to the position of the vestry. Q. _Why will the EASTERN winds make VESTRIES SMOKE, more than those from the west?_ A. Because they _strike against the steeple_, and _bound back_ to the vestry chimney: but _western_ winds cannot rebound over the roof of a church. (N. B. The _steeple_ of a church is always due _west_, and the _other_ end of the church due _east_; if, therefore, a _western_ wind rebound, it would rebound to the _west_, or _away from the church_, and not towards it.) Q. _Why does a HOUSE in a VALLEY very often SMOKE?_ A. Because the wind (striking against the surrounding hills) _rebounds back again upon the chimney_, and destroys its draught. Q. _What is the common REMEDY in both these cases?_ A. To fix a _cowl_ on the chimney top, to turn like a weather-cock, and present its back to the wind. Q. _Why will not a COWL always PREVENT a chimney SMOKING?_ A. If the wind be _strong_, it will keep the _opening_ of the cowl _towards the steeple or hill_; and then the reflected wind will _blow into the cowl_, and _down the chimney_. Q. _As a cowl is such a poor remedy, can any OTHER be devised?_ A. If the chimney flue can be carried _higher_ than the steeple or hills, no wind can enter the flue.