During a visit to Professor H.G. Harb at the University of Wisconsin, it was apparent that he had succeeded in obtaining fresh, clean chemisorptive layers of titanium by sublimation and chat that this could be adapted into an effective high vacuum pump. Two previous techniques of obtaining a chemisorptive layer of titanium, namely catholic sputtering and evaporation from the liquid droplet, have been extensively investigated and reported. Each of these seem to have inherent difficulties in stability and continuity of operation that appear to be eliminated or effectively reduced by the sublimation procedure. A development program was started at Brookhaven National Laboratory to investigate the possibilities of each sublimation of titanium as opposed to evaporation from the liquid.