It has been determined from extensive laboratory and field tests on the stability of coal suspensions in fuel oil that each installation must be given individual consideration if satisfactory results are to be obtained. However, no particular difficulty in devising equipment or operating routine for efficient use need be experienced. A sufficiently stable suspension of coal in oil for practical purposes can be prepared by dispersing 40 per cent coal by weight ground from 98 to 99 per cent through a 230-mesh screen in heavy fuel oil. Careful control of storage and handling temperatures is required for most successful operation. Combustion efficiency is likely to be slightly less than that of fuel oil. The best opportunity for the successful use of coal-in-oil suspension is in the larger plants with better operating personnel and more readily accessible equipment.