Attention is drawn to the difference in method of procedure necessary in developing large and small Diesel engines and to the greater obstacles met in systems injecting the charge directly to the cylinder in comparison with those employing precombustion-chambers. The antechamber fuel system used in the Hill engine is described as performing three functions: (α) to ignite and eject rich fuel gas into the main combustion space early in the combustion stroke; (b) to feed the cylinder combustion with air from the upper portion of the antechamber after the main part of the fuel charge has been ejected from the chamber; and (c) to cause violent turbulence and complete mixture of the charge by the large stream of gas issuing from the antechamber. Only the first of these three functions is accomplished by the ordinary precombustion-chamber. A recently developed automotive-type engine is described. Discussion of this paper and C. L. Cummins’ paper on Diesel Engines for Automobiles, which is printed on p. 105, will be found beginning on p. 290 of the September, 1930, issue of the S. A. E. JOURNAL.