235,138. Pontoppidan, C., and Bonde, H. P. June 5, 1924, [Convention date]. Cements, Portland, processes for making.- Aluminous cements are obtained by burning the raw materials in a rotary kiln which is heated by a gas flame in order to avoid excessive heating of the material bv direct radiation. The Specification as open to inspection under Sect. 91 (3) (a) includes also other methods of protecting the materials from direct radiation, such as (1) forming the flame in an extension of the kiln, through which the material does not pass, (2) surrounding the flame with an annular jet of cool air, (3) diluting the flame with inert gas or excess air, and (4) cooling the kiln shell at the point where radiation is greatest. This subject-matter does not appear in the Specification as accepted.