100 abstracts: engineering 



and interstate waters. The investigation was begun on the Great Lakes 

 because of the industrial and commercial importance of the lake cities 

 and the spread of typhoid fever by means of the enormous interstate 

 traffic for which these cities are responsible. A. J. McL. 



ENGINEERING. — The expansion and contraction of concrete while 

 hardening. A. T. Goldbeck, Office of Public Roads. Proceed- 

 ings of the American Society for Testing Materials, 1 1: 1911. 



This paper presents the results of micrometer measurements taken 

 on concrete while hardening. The specimens were 8 inches by 8 inches 

 in cross-section with a gage length of 50 inches. They were mixed 

 in different proportions, with varying percentages of water and were 

 stored under different conditions of moisture. Quantitative results of the 

 shrinkage in air and expansion while moist are shown graphically, the 

 initial measurements having been taken when the specimens were one 

 day old and continued at regular intervals. A. T. G. 



ENGINEERING. — Bituminous dust preventives and road binders. 

 Prevost Hubbard, Office of Public Roads. Yearbook of the 

 Department of Agriculture, 1910. 1911. 



The author, after mentioning bitumens as the most important class 

 of materials employed as dust preventives and road binders, divides 

 them into two main classes: (1) Native bitumens, (2) Artificial bitumens. 

 The treatment of the former for the purpose of making them suitable 

 for use on roads is briefly discussed, as is also the relative value of differ- 

 ent bituminous distillates and residues. This is followed by a classifi- 

 cation of bituminous materials with regard to their value as "dust pre- 

 ventives" or as "road binders." The conditions affecting the selection 

 of material are briefly outlined, followed by a description of the two 

 principal methods of application — the penetration method and the 

 mixing method. The author also briefly describes the character and 

 method of application of rock asphalt and manufactured bituminous 

 aggregates. C. S. Reeve. 



