In Fig. 212 the figures 8, 9, 10, etc., indicating the months, can be printed on the cards and thus leave to be inserted by hand each year only the short vertical markings indicating the relation of the weeks and the months.

Fig. 213 shows the weekly curve card used in the records of a dairy farm. The particular curve shown is for a prize Jersey cow which was being very carefully tested in the hope of breaking the world's record for milk production. The milk production each week is indicated here, in pounds, together with the butter-fat analysis taken at various intervals.

CURVES FOR THE EXECUTIVE

The days on which the butter-fat analysis were made are quite accurately indicated by the dots on the butter-fat curve. Figures for the milk production each week are given to hundredths of a pound in the appropriate column above, and the butter-fat analysis is given to one onehundredth of one per cent for each date on which the analysis was made. The grand total milk production for the year of the test is given at the foot of the column. Note the diagonal arrangement of the two headings, "Pounds" and "Per cent Butter Fat". This diagonal arrangement is a convenient one as it is easy to read and refers to each of two columns of figures, one column vertical and the other horizontal.

A card for each cow as indicated above is worth while in a modern dairy. Individual records are fundamentally necessary to efficient operation. There is such a wide variation in cows that unless they are care-