The report describes the development of techniques for the preparation of emulsions of No. 6 residual fuel oil and water. It also includes the preliminary design of a combustion test rig for studying the combustion of heavy oils and emulsions and pollutant emission produced by burning these fuels. Stable emulsions containing up to 30 percent water, by weight, were prepared from 9 samples of residual fuel oils. No emulsifying agents were required as the oils apparently contained natural emulsifiers. Emulsions containing basic additives were also prepared. The emulsions did not appear to break during atomization. The preliminary design of the combustion test rig showed that a rig could be constructed to operate with either combustion intensity or pressure drop comparable to that of a full-scale unit. This can be accomplished by varying the firing rate from 1.5 gph for constant combustion intensity firing to about 8.0 gph for constant pressure drop firing. A variable swirl-type burner was designed to provide the flexibility needed for this range of combustion conditions. (Author)