Document JJ739GrO7nZYNJzYaaD2M1rOZ

April 5* 1961 Mr. E. A. Dennison Johna-Manvlllo Corp, Gypsum Produots Division 22 East 40th Stroot Now York, N. Y. Door Mr. Donnisont This is to oortlfy that tho 4 foot wide squoro odgo gypsum sheathing^ manufaoturod by Bostvall Oypsum Company for tho Johna-Manvlllo Corp* la aado by tho aamo formula and to tho aamo spocifloationa as that which la mado in our plants for oalo undor our own labol* Tho porformanoo of tho shoathlng is oovorod by a roport of tho Pittsburgh Tasting Laboratory, datod Doo. 26 1959 undor tltlot Witnosslng Toots of loathing notarial for Roslstanoo to Raeking Undor Dry & Wot Conditions on 48" Wido, Squaro Edgo, 0no-half Inoh Thlok, Bostvall Gypsum Sheathing. Tory truly yours, BE3TWAL1 GYPSUM COMPANY CGS/tad ooi Mr. C. B. Abboy Mr. R. L. Smith G. Stmttloworth of Chomist SGP 0024700