The purpose of this investigation was to determine the effect of the operating variables of type of reactor, catalyst, ethylene feed concentration, temperature, and contact time on the products of oxidation of ethylene to ethylene oxide; and together with subsequent hydrolysis to evaluate the commercial feasibility of the manufacture of ethylene glycol. The review of the literature contained 10 references. The equipment employed was arranged as indicated in a general flow diagram for the system. A silver catalyst activated by barium peroxide was employed and prepared on No.7 and No.3 Valencia pumice as the carrier according to Wiseman. For the analysis of ethylene oxide the procedure employed was a modification of that suggested by Vaughan and Wiseman. The carbon dioxide content of the product gases was determined by absorption of the carbon dioxide by ascarite; moisture was removed by means of drierite. Data and Results: A summation was made of operating conditions, yields and conversion in the air oxidation of ethylene in a fixed bed and fluidized bed reactor as a function of type of catalyst, contact time, reactor bath temperature, ethylene feed concentration, employing a barium peroxide activated silver catalyst coated on No.3 and No.7 Valencia pumice , uncoated pumice, and mixtures of these catalysts. It was found advisable to employ a 50% mixture of catalyst-coated and uncoated carrier in the tests because of the tendency toward fusion of the catalyst particles when used alone as the reactor charge . An increase the ethylene feed concentration from 3 to 9 per cent does not seem to appreciably affect either the conversion or yield. / Ph. D.