THE ESTIMATING AND COSTING OFFICES 5 previous jobs, complete and in detail, should be faithfully kept and tabulated. Part of this tabulation is usually done in the working drawing office, and part of it either in the counting-house or, better still, the separate costing de- partment. A book of finished weights should be kept, showing the weight of each part or unit which it is practicable to consider separately. For instance, suppose it is a reciprocating engine installation and perhaps boilers, the record of this installation may be set down thus: Estimated I.H.P., Size of cylinders, Number and size of boilers, I.H.P. Cubic feet of cylinders' capacity, as a heading, which could be amplified considerably. Then would follow headings of the principal parts, such asc Main engines. Fittings on main engines. Auxiliaries in engine-room and in boiler-room. Fittings apart from main engines. Shafting, &c. Boilers. Fittings in boiler-room. Water in boilers. Condensing plant. Water in condensing plant. Spare gear. Outfit. Refrigerating plant. Electric plant. Each of these should be divided into as many sections as is found desirable. As an example again, take the heading " Main Engines "; this would be split up into sub-headings something like the following:—. Cylinders. Soleplates. Piston-rods. Air-pumps, &c. This "finished weight" book should be carefully indexed. Style of Job.—Again, the cost of a job depends a great deal upon the characteristics of the intending purchaser and his firm's practice. This may be illustrated by considering three firms known to the present writer—all well-known shipowners.