Bott-clay
The clay used for stopping up the tap-hole in the cupola. Any good, ordinary clay will answer for this purpose, but it requires more than ordinary care to bring it to the right condition for effective use. If too soft it is impossible to fill the hole with a firm plug, and if too hard it refuses to yield to the form of the hole, so that in either case there is danger, because, as the bottom fills, the pressure increases and the imperfect plug is forced out. Besides being of the right consistency, there should also be mixed with it a quantity of sea-coal; this prevents in a large measure the sputtering usually attendant upon the use of the raw clay. The operation of tapping is expedited also by this admixture of sea-coal, as it prevents to some extent the clay from baking hard, and for this reason is more easily picked out with the tapping-bar. See BOTT-STICK; TAPPING-BAR. Bott-stick, sometimes called a "bod-stick," is the tool used by the cupola-man for plugging the tap-hole with clay after sufficient or all the iron has been allowed to run from the cupola. It may consist of a long iron rod about 3/4 inch diameter, one end of which is formed into an eye for ease in handling, and upon the other is forged a flat button, about 2 inches diameter, made with a corrugated face in order that the clay bott which is pressed upon it may adhere thereto. For "stopping-in" over-large ladles it is almost necessary to have an iron bott-stick, but when small ladles are in use, and the hole is opened frequently, a long wood shaft may be substituted for the iron rod by either forming the button on a spike and driving it in the end, which is prevented from splitting by an iron band, or it may be formed on an iron socket made to receive the end of the shaft. The wood ones are much lighter and easier to handle than the iron ones. To use the bott-stick properly, see--first, that the button is cold and wet, a pail of water being kept near by for the purpose; second, that the clay bott is pressed firmly down upon it and worked with the hand into the form of a cone; and thirdly, that the back-hand be slightly raised, pressing the clay into the hole from the upper side. By this means whatever commotion takes place when the molten iron touches the wet clay is in the immediate vicinity of the tap-hole in a downward direction, thus avoiding all the unpleasantness and danger caused by the spray of metal, which is thrown in all directions when the bott is thrust carelessly into the hole with the stick held in a horizontal position. See BOTT-CLAY.