History AND DEVELOPMENT 25 
industry, the practice of fractional sterilization was abandoned 
for economic reasons. 
“The commercial part of the business also had its trials and 
tribulations in introducing a new and comparatively inferior 
product of comparatively high cost, and to overcome the prej- 
udices of both the trade and the medical profession, 
“The problem thus confronting the company was te ‘m- 
prove the product, decrease its cost and improve selling methods 
at the least possible cost.” 
At first this unsweetened condensed milk, of relatively thin 
consistency and pregnant with the cooked flavor resulting from 
its exposure to high sterilizing temperatures, failed to appeal 
to the public. who had become accustomed to the use of the 
sweet, thick and semi-fluid sweetened condensed milk. But of late 
years the demand for, and the manufacture of this product. 
evaporated milk, has increased rapidly, until today, in this 
country, its output by far exceeds that of sweetened con- 
densed milk. 
Originally this unsweetened sterilized condensed milk was 
labeled and sold under the name of “Evaporated Cream.” The 
Federal Food and Drugs Act of 1906 caused the name “Evapo- 
rated Cream” to be changed to “Evaporated Mill.” 
A further important step in the development of the manu- 
facture of condensed milk occurred with the introduction of 
the Continuous Concentrator, which machine was developed by 
the By-Products Recovery Co., of Toledo, Ohio. This company 
was organized in 1913 and their machine and process are covered 
by numerous United States patents. ‘The principle upon which 
the Continuous Concentrator is constructed and operates is as 
follows: 
“To rapidly move a film layer formation within a cylinder 
having a heated surface, having means for escaping vapors and 
means for keeping the surface bright and clean, cireumferentially 
and from the point of inlet to the point of outlet.” 
Another type of the film principle of continuous concentra- 
tion is represented in the Ruff Condensing Evaporator, manu- 
factured by the Cream Production Co., Port Huron, Mich. 
The Continuous Concentrator im its present improved form 
has reached a state of perfection that renders this machine appli- 
