It consists of two columns, _C_ the analyser, and _H_ the rectifier, placed side by side and above a chamber containing a steam pipe _b_ from a boiler _A_. This chamber is divided into two compartments by a horizontal partition _a_ pierced with small holes and furnished with four safety valves _e e e e_. The column _C_ is divided into twelve small compartments, by means of horizontal partitions of copper, also pierced with holes and each provided with two little valves _f_. The spirituous vapors passing up this column are led by a pipe _i_ to the bottom of the second column or _rectifier_. This column is also divided into compartments in precisely the same way, except that there are fifteen of them, the ten lowest being separated by the partitions, which are pierced with holes. The remaining five partitions are not perforated, but have a wide opening as at _w_, for the passage of the vapors, and form a condenser for the finished spirit. Between each of these partitions passes one bend of a long zig-zag pipe _m_, beginning at the top of the column, winding downwards to the bottom, and finally passing upwards again to the top of the other column, so as to discharge its contents into the highest compartment. The apparatus works in the following way: The pump _Q_ is set in motion, and the zig-zag pipe _m_ then fills with the wash or fermented liquor until it runs over at _n_ into the highest compartment of column _C_. The pump is then stopped, and steam is introduced through _b_, passing up through the two bottom chambers and the short pipe _F_ into the analyzing column, finally reaching the bottom of the other column by means of the pipe _i_. Here it surrounds the coil pipe _m_ containing the wash, so that the latter becomes rapidly heated. When several bends of the pipe have become heated, the pump is again set to work, and the hot wash is driven rapidly through the coil and into the analyzer at _n_. Here it takes the course indicated by the arrows, running down from chamber to chamber through the tubes _h_ until it reaches the bottom; none of the liquor finds its way through the perforations in the various partitions, owing to the pressure of the ascending steam. As the liquid cannot pass through the holes in the partitions it can only pass downward through the drop-pipe tubes _h_. By this means the mash is spread in a thin stratum over each partition to the depth of the seal _g_ and is fully exposed to the steam forcing its way up through the holes, the alcohol it contains being thus volatilized at every step.