A. Because the bottom and back are _covered with soot_; and the _black soot_ rapidly _absorbs the heat_ of the glowing coals. Q. _Why should the FRONT and LID of a SAUCEPAN be clean and BRIGHT?_ A. As they do not come in contact with the fire, they cannot _absorb heat_; and (being bright) they will not suffer _the heat to escape_ by radiation. Q. _In what state should a SAUCEPAN be, in order that it may BOIL QUICKLY?_ A. All those parts which _come in contact with the fire_ should be covered with _soot_, to absorb heat; but all the _rest_ of the saucepan should be as _bright as possible_, to prevent the _escape of heat_ by radiation. Q. _Why is it said that "SATURDAY'S KETTLE BOILS the FASTEST?"_ A. Because on Saturday the _front_ and _top_ of the kettle are generally _cleaned_ and _polished;_ but the _bottom_ and _back_ of the kettle are _never_ cleaned. Q. _Why should NOT the BOTTOM and BACK of a kettle be CLEANED and polished?_ A. Because they _come in contact with the fire_, and (while they are covered with black soot) _absorb heat freely_ from the burning coals. Q. _Why should the FRONT and TOP of a kettle be CLEAN and well polished?_ A. Because polished metal _will not radiate heat_; and, therefore, (while the front and top of the kettle are well polished) _the heat is kept in_, and not suffered to escape by radiation. Q. _Why is the INSIDE of a KETTLE and SAUCEPAN WHITE?_ A. _White will not radiate heat_: if, therefore, the inside of a boiler be _white_, the liquor in it is _kept hot much longer_. Q. _Why is the BOTTOM of a KETTLE nearly COLD, when the WATER is BOILING HOT?_ A. Black soot is a very _bad conductor of heat_; and, therefore, the heat of the boiling water is some considerable time, before it gets _through the soot_ which adheres to the bottom of the kettle. Q. _Why is the LID of a KETTLE so intensely HOT, when the water boils?_ A. The bright metal lid of the kettle _is an admirable conductor_ of heat; and, therefore, _the heat from the boiling water pours into our hand_ the moment we touch it. Q. _Show the benefit of SMOKE in COOKING._ A. The carbon of the fuel (which flies off in smoke) naturally _blackens_ all culinary vessels set upon the fire to boil, and thus renders them fit for use. ("Culinary vessels" are vessels used in kitchens for cooking, as saucepans, boilers, kettles, &c.) Q. _How does SMOKE make culinary vessels FIT for USE?_ A. If it were not for the _smoke_, (which gathers round a kettle or saucepan) _heat would not be absorbed_, and the process of boiling would be greatly retarded. Q. _Why is boiling water KEPT HOT best in a BRIGHT METAL pot?_ A. Because bright metal being a _bad radiator_ will not _throw off the heat_ of the boiling water _from its surface_. Q. _Why is WATER KEPT COLD in summer-time in a BRIGHT METAL pot, better than in an EARTHEN vessel?_