The packing-house method of taking the temperatures of hams by means of a pointed, metal-capped thermometer which is thrust deep into the bodies of the hams has already been referred to, but deserves to be described somewhat more in detail, as it will be at once apparent that this manipulation furnishes a ready means whereby hams may become infected with putrefactive bacteria. The construction of a ham thermometer is shown in figure 4. [Illustration: A. B. FIG. 4.—Diagrammatic views showing construction of ham thermometer. A, front view, showing open space between metal point and mercury bulb, which becomes filled with particles of meat, grease, and dirt; B, side view.] The instrument consists of a glass thermometer inclosed in a metal case, the front portions of the case being cut away so as to expose the scale above and the mercury bulb below. As was explained before, the thermometer is thrust deep into the body of the ham so that the pointed end containing the mercury bulb rests beside or a little behind the upper portion of the femur, the bone being used as a guide in introducing the thermometer. Ham temperatures are taken at three stages in the preparation for cure—(1) on the hanging floor, just before the hams go to the chill rooms, in order to determine the amount of heat lost prior to chilling; (2) on leaving the chill rooms, in order to determine the thoroughness of the chill; (3) on the packing floor, just before the hams are placed in pickle, as a further check on the thoroughness of the chilling.