also upon its frequency of occurrence in a day's work.
An expert observer can, on many kinds of work, time two or three men at the same time with the same watch, or he can operate two or three watches—one for each man. A note sheet can contain only a comparatively few observations. It is not convenient to make it of larger size than the dimensions given, when a watch-book is to be used, although it is perfectly feasible to make the horizontal rulings 8 lines to the inch instead of 5 lines to the inch as on the sample sheet. There will have to be, in almost all cases, a large number of note sheets on the same subject. Some system must be arranged for collecting and tabulating these records. On Tables 2a and 2b (pages 160 and 161) is shown the form used for tabulating. The length should be either 17 or 22 inches. The height of the form is 11 inches. With these dimensions a form may be folded and filed with ordinary letter sheets (812 inches by 11 inches). The ruling which has been found most convenient is for the vertical divisions 3 columns to 118 inches, while the horizontal lines are ruled 6 to the inch. The columns may, or may not, have printed headings.
The data from the note sheet in Fig. 2 (page 151) is copied on to the table for illustration. The first columns of the table are descriptive. The rest of them are arranged so as to include all of the unit times, with any other data which are to be averaged or used when studying the results. At the extreme right of the sheet, the gross times, including rest and
