490 KANSAS CITY REVIEW OF SCIENCE. 



on three inches of sand. The spaces between were rammed full of sand, and a 

 coating of asphalt paving cement spread over the surface. The cost was $1.75 

 per square yard. 



These two contracts were not preceded by any special pubhc consideration 

 of the subject generally, and were, as to kind, mainly the result of accident and 

 individual interests. 



The question of the proper kind of pavements for our streets came up in June, 

 1882, prominently in connection with the improvement of Sixth Street, between 

 Delaware and Bluff Street. This street had just been regraded so as to form a 

 new avenue for travel to and from West Kansas, and with the expectation, which 

 has since been realized, that it would immediately become a main thoroughfare and 

 leading business street. 



Under the law of this city, the paving of any street cannot be done by the 

 authorities until the owners of property along the street, representing the major- 

 ity of the front feet (exclusive of non-resident ownership) shall formally petition 

 the common council to have the work done. It is also necessary that the prop- 

 erty-owners shall specify substantially what kind of pavement they want laid 

 down. The entire cost of the work is assessed against the property fronting on 

 the street. 



The property-owners on Sixth Street selected a committee to consider the 

 various kinds of pavements suggested, and finally decided, upon my recommend- 

 ation, to put down a substantial concrete base nine inches thick, with a cedar 

 block seven inches long for a wearing surface. The specifications which I pre- 

 pared at this time have governed, without material change, all work of this char- 

 acter done since then, excepting that the thickness of the concrete foundation is 

 made on some streets six inches, instead of nine, as on Sixth Street, and six-inch 

 blocks have been put down on some of the streets instead of seven. The lead- 

 ing features of the cedar block pavement, put down in this city, are as follows : 



The roadway is excavated to proper depth, and made to conform to the 

 shape to be given to the finished surface of the pavement. Care is taken to 

 secure, as far as possible, uniform density of the sub-grade, by the use of a two- 

 ton roller, (the only one available), and by filling in soft spots with broken stone 

 and ramming them down into the soil. 



On this sub-grade is placed a layer of hydraulic cement concrete nine inches 

 thick on some streets, and six inches thick on others, depending principally on 

 the character of the formation, location, and character of the street, whether it 

 is a business thoroughfare, or a street in a residence part of the city. Tn an excep- 

 tional instance the depth of the foundation has been reduced to four and one-half 

 inches by the property-owners, although, generally, the popular disposition has 

 been in favor of the nine-inch base on streets of all kinds. 



The concrete is composed of five parts by measure, of clean lifnestone, broken 

 to go through a two and one-half inch ring, and two parts of clean coarse river 

 sand, with one part of approved hydraulic cement. The sand and cement are 

 thoroughly mixed dry, and then wet, and the mortar spread over the stones, which 



