244 DEPARTMENTAL KEPORTS. 



Chemistry. This laboratory is now in full operation, and any citizen (jf 

 the United States interested in the construction of public higlnvaj's 

 can have road materials tested free of charge. 



The methods emjiloyed in this laboratory are very practical and in 

 many respects original, and the work done has proved most satisfac- 

 tory. The general methods employed are briefly as follows: 



When an application to have a sample tested is received at the 

 laborator}^ a blank form is sent to the applicant to be filled out with 

 necessary information regarding it. The sample is then subjected to 

 an abrasion test to determine its resistance to wear; a cementing test 

 for determining its cementing or binding jjower; a toughness test; 

 and a hardness test. Other information regarding the sample is also 

 secured and furnished to the applicant, such as its density, absorp- 

 tiveuess, and proper nomenclature. 



When expert advice is asked as to the suitabilitj^ of two or more 

 samples for a particular road, a blank form for making a fourteen- 

 day census of the volume and character of traffic over that particular 

 road is sent to the applicant to be filled. When this information is 

 received at the laboratory a request is made to the Weather Bureau to 

 supply a record of the meteorological conditions obtaining in the par- 

 ticular localit}- through which the road passes. From a study of these 

 combined data the expert in charge of the laboratory is able to make a 

 thoroughly scientific selection of the material best suited for the i^ar- 

 ticular road. This method of selection eliminates, as far as possible, 

 any personal error, and makes what has been heretofore a very com- 

 plicated problem one of simple engineering. 



Up to the present time about 100 samples of rock have been received 

 and tested at the laboratory, and applications for tests are being 

 received in steadily inci-easing numbers. Most of the machinery and 

 appliances had to be especially built for the laboratory. These were 

 designed by Mr. L. W. Page, who is in charge. 



URGENT DEMANDS FOR OFFICE ASSISTANCE. 



The state of public opinion regarding the work of this Office, the 

 character of the demands made upon it, and the pressing need for an 

 extension of the work can best be shown by a few brief quotations from 

 the thousands of letters, newspaper clippings, and copies of resolu- 

 tions on file in the Office. 



FROM CORRESPONDENTS. 



Mr. James W. Thompson, a prominent gentleman of Louisville, 

 Ky., in acknowledging a copy of our last Yearbook article, says: 



I wish to thank you, the Department, and the Hon. ]Martin Dodge for the help 

 yon have given ns in Kentucky on the good-roads (juestion, as without it we could 

 not have accomplished what we have. 



I hope ( ongress will make a more liberal appropriation for the maintenance of 

 your Office, which I think is one of the most important connected with the Gov- 

 ernment. What you have accomplished with the small appropriation you have is 

 something wonderful. 



Mr. Arthur T. Neale, director of farmers' institutes for Delaware, 

 writes : 



The managers of the farmers" institute would like to give much time to meet- 

 ings devoted to the road ((ue.stion this winter. * * * May I as'c whether lec- 

 turers can be secured for institute work from among those holding positions 

 under youV 



