Seve ntee n brands of masonry cement were tested fo r so un d ness, stre ngth , consistency, fi ne ness, tim e of setting, shrinkage, water re pe ll ency, wate r r ete nt io n, autocla,·c cx pa nsion, air ent rainm ent, and resistance to freezin g and t hawin g. \1 0rta rs were pro po rti o ned both by weight and by volum e. Au toc lave tests indi cated po te nt ia l unsoundness in so m c of t he cem ents. Air e ntrained in t h e mort ar \\"as effective in in creasing t he abilit y to withst a nd freezin g and t h awing. The shrinkage of t h ese ce me nts differed g reat ly. The r es ults of tests indicated a lso t hat t he propert ies of t hese m aso nry ce ments ,,·ere ap preciab ly diffcrent from those prcv ious ly re ported in 1934.