ESTIMATING AMOUNT OF CAPITAL INVOLVED C It is usually not difficult to estimate with reasonable accuracy how much plant will be necessary, provided that the work ing conditions are well established. Where drilling is to be done, the maximum and mini mum average performance per drill must be de termined from an inspection of the local condi tions. It should be borne in mind that under ordinary working conditions from 10 to 20 per cent of the drilling equipment will be in the shop for repairs, and that a surplus of at least 15 per cent should be provided. Extra drills can easily be procured at comparatively short notice; but extra steam or air service cannot, and therefore a more liberal margin should be provided for the boilers and compressors than the actual number of drills to be taken on. Liberal allowance should be provided for pipe lines and for connec tions, whenever the work is to be done in cold weather. • For the process of loading, the grab bucket, steam shovel, derrick and skips are the logical types of equipment, with the advantages lying in the order named; and given the conditions and class of work, a fairly close approximation of the cost of equipment can be very rapidly made. It is necessary to be very careful to make a proper allowance for lost time. It has been aptly observed that a steam shovel can put material on cars about as fast as you can take the cars away from it; and in earth work, this is generally true. Therefore the performance per unit of equipment, and consequently the size and amount of equipment necessary for the work, will depend largely upon the proper layout of the transportation facilities. From one-third to two thirds the theoretical capacity of a steam shovel is about the range of what it may be expected to do in average practice. It is proper here to remark parenthetically, that, in estimating, it is not safe to assume that the practice will be extraordinarily good.
C C—Cash Capital. On a good-sized piece of work, $200.00 for petty cash on a job is ordi narily ample to take care of express charges, etc. The amount of the pay-roll per month will depend upon the number of men employed; man when monthly settlements are made about two weeks after the end of the month, this amount will have to be "carried," so that about half or two-thirds of the average pay-roll for the entire job will have to be considered as continually losing interest.