[82 POPULAR SCIENCE MONTHLY. 



is purchased under specifications that require the analysis of a sample 

 that must accompany every bid, and the determination of the heating 

 power of a sample from every consignment. Lubricating oils, boiler com- 

 pounds, samples of steel and other materials are analyzed and the 

 laboratory is also equipped for the chemical and physical testing of 

 cements. 



Other departments of municipal work are taking up the laboratory 

 idea. The Sewer Department of Worcester, Mass., has two laboratories. 

 One is located at the disposal works and is devoted wholly to the super- 

 vision of the process of treatment of the sewage. The other occupies 

 attractive rooms in the City Hall. Here a great variety of work is under- 

 taken. During the year 1899 more than a hundred carloads of cement 

 were used by the department, and over eight thousand samples were 

 tested for tensile strength; many chemical analyses were also made. 

 Bricks were frequently tested for absorption, and several samples of steel 

 used in the construction of shovels and offered to the department by dif- 

 ferent dealers were analyzed. Coal, oil, lime and many other materials 

 purchased by the department were analyzed. In addition to this, over 

 seventy-five samples of butter and oleomargarine were examined for the 

 Department of Milk and Butter Inspection, and a number of water 

 analyses were made for the water department. A large amount of 

 experimental work was carried on in connection with the problem of 

 sewage disposal. Both laboratories are under the general direction of 

 Mr. Harrison P. Eddy, Superintendent of Sewers. 



It seems apparent, therefore, that the laboratory is destined to be 

 an important factor in municipal engineering as well as in municipal 

 sanitation, and it is not difficult to foresee a time when every city of 

 importance will be provided with a laboratory equipped in accordance 

 with its needs. In large cities, work of this kind is preferably spe- 

 cialized and distributed through different departments, in order that it 

 may be under the control of those directly interested in the results, 

 but in small cities, all the analytical work can be more economically 

 accomplished in a single laboratory. In such a laboratory the work 

 would cover a very broad field. Coal, cement, oil, brick, asphalt and 

 various structural materials would be tested before purchase and during 

 delivery; illuminating gas regularly examined; water, milk and various 

 food products analyzed to determine their purity and healthfulness; bac- 

 teriological cultures made for diagnosis of diphtheria, typhoid fever, 

 tuberculosis and kindred diseases; disinfection of buildings supervised, 

 etc. All this would require the services of an engineer, a chemist and 

 a bacteriologist, or of these three combined in one person. The expense 

 of such an institution would be small in comparison with the saving that 

 would result to the citizens in the purchase of supplies and in the 

 protection of the public health. 



