638 THE JOURNAL OF GEOLOGY. 



form a binding cement of good quality, may be made to do good 

 service in road construction when mixed with a small quantity 

 of rock powder obtained from some other stone. As this pow- 

 der need not exceed one tenth of the material used in road 

 construction, it need not involve great cost, even if brought 

 from a considerable distance. 



Professor Shaler has called attention to the use of bricks for 

 highways. They have been used for centuries in Holland, and 

 it now seems likely that in the lowlands of the South this kind 

 of pavement may come to be of great value. This makes it 

 important that the laboratory should include in its investigations 

 a careful study of the clays of the country, with reference both 

 to distribution and burning qualities. Much information is at 

 hand concerning the clays of the country, but little attention 

 has been paid to this phase of their use. 



During the present year an officer of the Survey will be 

 detailed to take charge of the investigation of highway mate- 

 rial in the laboratory at Cambridge, Mass. The establishment 

 of a national laboratory will be brought to the attention 

 of congress, and a request made for a suitable appropriation. 

 The entire expense would probably not exceed $15,000 for the 

 first year, and $10,000 a year thereafter. It would seem that 

 such a laboratory would speedily become a source of public 

 information concerning highways, and that it would prove to be 

 of great value to the country. R. D. S. 



