88 REPORTS OF INVESTIGATIONS AND PROJECTS. 



cement i8 inches thick and completely separated, both at the bottom and 

 sides, from the foundation walls of the building by a layer of 6 inches of dry 

 sand, which, it is hoped, will prevent the vibration within the block from 

 passing into the building. It is too early to offer conclusions upon the 

 success or failure of this scheme, but preliminary runs with a 75-horsepower 

 engine, which was not by any means in perfect adjustment, do not cause a 

 noticeable disturbance on the floor above. 



The remaining features of the laboratory contain little which is novel or 

 of general interest. The main purpose has been to provide a number of 

 independent laboratories, each adapted for a single research to be conducted 

 by one investigator, with or without an assistant, and each laboratory is pro- 

 vided with a separate study immediately adjoining. Inasmuch as the labora- 

 tory is devoted exclusively to research problems, large general rooms, such 

 as are commonly found in university laboratories, are conspicuously absent. 

 At the same time, an attempt has been made to attain the maximum of 

 elasticity in providing for future changes to meet the requirements of 

 research which may not be foreseen at this time. Many of the subdividing 

 walls of the building contain vertical flues of vitrified sewer pipe, through 

 which communication may be had from one floor to another for gas, water, 

 compressed air, or electrical transmission, or for carrying away fumes. 

 Other walls are of very light construction, which could be removed to enlarge 

 particular rooms or to redistribute laboratory space should occasion require. 

 Elaborate permanent fixtures which, while convenient for one research, may 

 be unnecessary in another have been avoided. 



Bquipment. — The equipment of the laboratory is a special and somewhat 

 complicated problem, of which only the merest outline can properly be given 

 here. In general, each individual laboratory is served with electric and 

 other power according to its needs, the sources of supply being a direct- 

 current generator of 623^2 kilowatts capacity and alternating current from 

 the city mains which can be used as such through transformers or rectified 

 through mercury rectifiers, which have been found to work very successfully 

 and economically. Where constant conditions are required, 5 large storage 

 batteries (of 56 or 112 volts each) can be used separately, in parallel, or in 

 series, as occasion may require. Any or all of these sources of supply may 

 be furnished at one time to any laboratory room in capacity sufficient for all 

 ordinary requirements. Facilities are also provided for compressed air at 

 various pressures from 4,000 pounds downward, steam, illuminating gas, 

 vacuum, etc., wherever needed. The optical work of the laboratory, which 

 is required by all the investigations of a mineralogical character, is provided 

 for in special dark-rooms with proper facilities. 



Where both physical and chemical methods require to be applied upon the 

 same problem, separate rooms are provided wherever possible in order that 

 the chemical fumes may not cause deterioration in the instruments required 



