26 .Februar
Dear Prof. Allen,
I am sending you the only paper on the method of
making Sediment hard. The author is working out just
another paper and if you will write ^im certainly will
be gl ad to give you any advise.
LLnesrely yours
Prof. pr. F. Prsvermann.
To Mr. Victos
Al 1 en,
St.
Louis University
St. Louis Mo.