The two sides of the roulette table are duplicates of one another, each of them being divided something like a chess-board into three columns of squares, which amount to thirty-six; the numbers advance arithmetically from right to left, and consequently there are twelve lines down, so as to complete a rectangle; as 1, therefore, stands at the head, 4 stands immediately under it, and so on. At the bottom lie three squares marked 12 p, 12 m, 12 d, that is, first, middle, and last dozen. Three large spaces on each side of the numbers are for red and black; even and odd; _manque_ and _passe_, that is, the numbers in the first and second half respectively from 1 to 18, and from 19 to 36 inclusive. At the top of each board is zero, which sweeps all stakes, except those on the even chances, into the coffers of the bank. The stakes having been made a croupier says: "_Le jeu est fait, rien ne va plus_." The wheel is set in motion. At the same time a croupier sends the ball flying round the cylinder, the roulette wheel bearing the numbers being made to revolve in an opposite direction. The ball eventually falls on to the wheel, and as the latter slackens its speed, enters a compartment, the number of which is announced thus: "_Dix-sept, rouge, impair et manque_." When zero is announced all the money on the table is annexed by the bank with the exception of that staked upon the even chances red or black, odd or even, _passe_ or _manque_--the sums on these are moved to the edge of the board, being _en prison_ till the next coup, when they are taken or released according to the colour and chance which wins. The odds laid by the bank work out as follows:-- Stakes placed on any number or on zero are paid at the rate of 35 to 1--a player on the numbers is therefore taking 35 to 1 about a 36 to 1 chance, which must be to his prejudice in the long-run--on any four numbers 8 to 1, on any six numbers 5 to 1. Red or black, odd or even, _passe_ (the numbers after 18) or _manque_ (the numbers before 18) are even-money chances. The dozens and columns are 2 to 1 chances. Stakes are often placed _à cheval_, that is to say, on two adjoining numbers, which together are paid at the rate of 17 to 1. The red numbers and the blacks are unequally divided in the columns. The centre column contains eight black and only four reds; the first column has six reds and six blacks; while in the last column there are eight reds and four blacks. Professor Karl Pearson, when making an exhaustive study of the laws of chance, drew up a series of elaborate tables, with the intention of comparing the results of a number of spins of the roulette wheel with those produced by drawing numbers from a hat and tossing with coins.