of 46 years of dependable inspection and testing service to 
industry. 
Founded in 1881 by William Kent and William F.Zimmer- 
man, under the firm name of Kent & Zimmerman, mechan- 
ical engineers, it was later acquired by Capt. A. E. Hunt and 
Geo. H. Clapp, who inaugurated the unique service of inspec- 
tion of materials, testing of machinery and metals, and chem- 
ical analyses—a service upon which the business was built. 
Pittsburgh Testing Laboratory Building, 
Stevenson & Locust Streets, 
Pittsburgh, Pa. 
Industry found their services of great value in making 
independent inspections and tests, free from all bias or exag- 
geration, and the scientific methods by which they pursued 
their investigation soon won the confidence of all industry. 
In 1891, it was made a limited partnership under the 
name of Pittsburgh Testing Laboratory, Limited, and in 
1907 was incorporated under the laws of Pennsylvania.