IV PREFACE 



The scientific knowledge embodied in the present book has 

 been acquired, from time to time, tlirough work done by various 

 investigators at different Experiment Stations and by leading 

 scientists of the Federal Dairy Division. 



It may be added that the statistics and tables given in this 

 work have been quoted from noted, reliable authorities. 



The authors are indebted to the following companies and 

 individuals for the use of electro t^-pes : Cherry Brothers, Cedar 

 Rapids, Iowa; Waterloo Cream Separator Company and Iowa 

 Separator Company, Waterloo, Iowa; Vermont Farm Machine 

 Company, Bellows Falls, Vermont; Burrell & Company. Little 

 Falls, New York; Empire Cream Separator Company anrl Jensen 

 Creamery Machinery Company, Bloomfield, New Jersey; 

 Dairy Queen Mfg. Company, Flora, Indiana; Elyria Enameled 

 Products Company, Elyria, Ohio; Rice & Adams, Buffalo, 

 New York; Worcester Salt Company, New York City; Russell 

 & Hastings, Madison, Wisconsin; Louis F. Nafis, Creamery 

 Package Company, Borden & Selleck Company, De Laval 

 Separator Company, Arnold & Company, Diamond Crystal 

 Salt Company and Davis-Watkins Dairymen's ^Ifg. Compan\', 

 Chicago; Kirschbraun & Sons, Omaha, Nebraska; Professor 

 M. Mortenson, Ames, Iowa; and Strawberry Point Creamery, 

 Strawberry Point, Iowa. 



G. L. McK.^v. 



.\PRIL, 1022. 



C. L.ARSEN. 



