are spread out in a layer in a box. The mass is then thoroughly mixed together and loaded out into a wheelbarrow, deposited in place, and rammed until the mortar flushes to the surface. The cement is required to stand thirty-five pounds tensile strain per square inch after twenty-four hours. The brands used have been "Fort Scott," Kas., "Milwaukee," and various kinds of Louisville. On the surface of the concrete, which is made to conform to surface of street, a layer of sand is spread about one-half inch deep, or sufficient to fill up all the minor irregularities of the surface of the concrete, and make an even bearing for the blocks. The blocks are of white cedar, varying from four to eight inches in diameter, and are required to be cut from good sound live timber. They are usually seven inches long when set on nine inches of concrete, and six inches on the lighter base. They are sawn with parallel ends by gang saws, and are laid up as close together as practicable in the street. The interstices between the blocks are twice swept full of gravel, which ranges in size from one-quarter to three-quarters of an inch, and rammed down with round-pointed iron rods. After the first ramming, the surface of the block is made smooth and uniform wherever it may be uneven by going over it with a light paving rammer.

Asphalt paving cement, composed of coal-tar, distilled at 300° to 400°, and mixed with fifteen percent of mineral asphalt, is poured hot over the pavement, filling up all the minor interstices between the blocks. A thin coating of sand is then thrown over the surface before the asphalt dries.

The first prices at which this kind of pavement was let were $3.25 and $2.96 per square yard, for parts of Fifth and Sixth Streets, in the spring of 1882. This was for seven inch blocks on nine-inch concrete. Since then the cost of this work has been constantly decreasing with each successive letting. The last work contracted for was let at $2.44, and the average price paid during the season was $2.56. For six-inch blocks on six-inch concrete, the price has varied from $2.32 on the first, to $2.18 on the last contract let.

The ordinary wages for common labor has been $1.75 per day. The materials used cost about as follows: Seven-inch cedar blocks, eighty to eighty-five cents per square yard measured in the street, and six-inch blocks about seventeen cents less. For gravel, ten to twelve cents per square yard of pavement with seven-inch blocks. For asphalt paving cement, fifteen to eighteen cents per yard. The broken stone for concrete costs $1 per cubic yard, and sand about the same. Cement varies from $1 to $1.25 per barrel of about 260 pounds. The concrete in place is worth about $3.50 to $3.75 per square yard. One block of seven-inch cedar block pavement has been laid during this year on one-inch boards with four inches of sand underneath at a cost of $1.95 per square yard.

Observations of the wear of cedar block pavement with concrete base show a good, smooth surface and very uniform wear.

Blocks taken up at the intersection af Fifth and Main Streets, in the center of the business part of city, eighteen months after laying, showed a very regular wear of one-quarter to three-eighths of an inch. Blocks taken up for water and gas connections on the most crowded parts of Fifth and Sixth Streets, where

nearly all the heavy loads are confined to the ten and one-half foot strip of paving between the railroad track and the curb, show a wear of about three-eights of an inch in nearly two years.

There has been no repairing done on these streets, and there is no indication that any will be for some time. At all places where the pavement has been broken into, the concrete is found to be hard and compact. In one instance it was carrying the traffic of the street over a hole four feet across underneath. The bituminous concrete between the blocks has always appeared well formed, with but few voids occasionally near the bottom. The blocks are so thoroughly fastened together that sections of four to six square feet have been taken up with. out breaking. No swelling of the blocks and raising from the concrete has been observed. In very cold dry weather fine cracks appear running nearly directly across the surface of the pavement. They usually occur on steep grades and open from one to one and one-half inches if the extreme low temperature continues, but close up again with warmer weather.

The first stone pavement laid after the Medina stone, on a part of Fifth Street, was on a part of Bluff Street. Owing to the exceptional location of this street, no petition from adjoining property-owners could be expected, and in view of the public importance of this thoroughfare an appropriation of $15,000 was made out of the general fund to pave it. It was expected that a sufficient thickness of the old MacAdam metal would be found to form a good foundation on most of this street, considering the tons of broken stone that had been hauled there during the previous years. In the absence of this the specifications called for a six inch concrete foundation, which, in fact, was found necessary over the whole street. On this was placed a layer of two to four inches of sand. Rectangular blocks of the Argentine, or other good quality of native stone, was used for the wearing surface on my recommendation. The work could not be put under contract until late in the season, and consequently the eastern half, below Sixth Street, was prosecuted during the worst kind of winter weather-with the subgrade constantly wet from side-hill drainage, rains and snow, and was dug up to considerable extent by the gas company.

New quarries were opened and much of the stone laid in frosty condition on frozen sand; only the most urgent public necessity could justify doing the work under these circumstances. The western half remained unpaved and in nearly impassable condition, until early in the following spring. Meanwhile the large volume of the heaviest traffic in the city was turned on to the new pavement. This pavement cost $2.95 per square yard, or about $2.35 exclusive of the concrete base.

A line of three-inch agricultural tile drain pipe was laid along each side of the street near the gutters-that on the east side being for the purpose of draining the wet soil at the base of the hill, along which it runs-and that on the west side for sub drainage and protection of retaining-wall.

Observations of the wear of this paving show numerous minor depressions of the surface, principally along the east side, and are due partly to unequal

wear of the blocks, end partly to settling of some of the numerous excavations made and imperfectly refilled, just in advance of the pavement. The principal objection to this stone is the variations in quality and consequent unequal wear. Although the effort was made to secure, by inspection at the quarries and on the ground, uniformity in quality, still the result shows that this has not been fully attained, and is, I think, impracticable for large quantities under the existing conditions. A large proportion of the stones indicate good wearing qualities, and will probably last for fifteen years, but the more rapid wear of the softer kinds makes a rough pavement and brings undue wear upon the others.

This material is extensively used by the street railroad companies for paving between their tracks, without any special selection as to quality used or shape of blocks, and without adequate foundation or care in laying.

A very superior quality of sandstone block pavement has been laid during the past season on Union Avenue. The stone is a firm, small-grained, metamorphic sandstone of pinkish color, quarried in the foot-hills of the Rocky Mountains, in Boulder County, Col. It lies in well defined and fully separated ledges varying in thickness from one inch to several feet. The ledges selected for paving stones are from three to four and a half inches thick, and the blocks are cut out from eight to twelve inches long and six inches wide. The Union Avenue pave

ment has a concrete base of nine inches, with two inches of sand on top, and has the joints swept full of sand. The side joints are smooth, corresponding to the natural top and bottom beds of the stone in place, and the ends re-cut to lay to one-half inch joint.

crete.

laid.

This pavement cost $5.38 per square yard, or about $4.25 exclusive of conThe stone costs on cars here, about $2.50 per square yard, measured as Portions of this pavement that has been under heavy and continuous traffic since first put down, indicate excellent wearing qualities. A part of Mulberry Street, West Kansas, has also been paved with this stone, on a nine-inch bed of sand, with a well prepared sub-grade. East Ninth Street, from Main to Grand Avenue, is now being paved with the same material, on six inches of concrete. The grades on these two blocks are eight and thirteen per cent.

Walnut street from Twelfth to Twentieth, about 4,600 feet, was macadamized last year. The stone was carefully selected for hardness, and was broken to size from three and one-half inches to two inches. They were spread on in three layers, one of five and two of four inches each, making a thickness when rolled of thirteen inches at centre of roadway, and eight inches at gutters. The top layer is of very hard flinty rock and was mixed with a binding material of sand and clay; the only roller available was an old one weighing about 4,000 pounds and was altogether too light to compact the metal. There was consider

able travel over this street while the work was in progress, forming well-defined ruts in the loose stones along the center. The street has been carrying a large and heavy traffic for a year now, and is in very good condition, although it has had no repairs at all. This work cost sixty-three cents per square yard.

VIII-32

A portion of Hickory Street, in West Kansas, about half a mile long, was paved under the Telford-MacAdam specifications, at a cost of seventy-eight cents per square yard. It has had no repairs since completed, and has been carrying a very large traffic with reasonably satisfactory results. The character of the pavement on these two streets, was due, in the case of Walnut Street, to the strong preference of a few active property-owners; and in the case of Hickory Street to the impracticability of getting a majority of the property-owners to agree upon any better kind.

A large amount of good macadam pavement might properly be put down on certain streets, provided the city had a heavy steam roller to use in construction, and, in addition, a well organized and equipped force to make repairs. Under present circumstances I think it is bad policy to improve streets-especially business streets like these-in this way.

All the materials used and the execution of the work is under constant supervision-one, and frequently two, inspectors being assigned to each piece of work. The whole work is under the immediate charge of the Superintendents of Construction, and care is taken to insure good workmanship and a substantial compliance with the specifications throughout.

The drainage system of the street surface is from the center each way to the gutters, and along the gutters to sewer inlets at nearest street corners.

The standard form for paved streets makes the pavement at the center of the street level with the curbs, and thence sloping down on curved lines to eight inches below this level at the curb line, excepting in the case of macadam streets, which are designed to have twelve inches fall to the gutter. Considerable variation, however, is found to be necessary on account of the existence of single or double lines of street railway tracks along the center of the roadway, and frequently on account of streets where the old established grade varies from "level across" to three feet higher on one side of the roadway then on the other. Some modifications are advisable, too, in cases of steep longitudinal grades, but the general purpose has been not to make the cross-slope greater than eight inches in eighteen feet, and to make the gutter not less than six nor more than twelve inches deep.

Starting in the spring of 1882 with seventy-eight miles of dirt streets out of the total of ninety-three miles in the city, and the remaining fifteen miles of old Telford-MacAdamized streets which included all of the business streets, the work of paving done since then has been at follows:

We have taken up five and two-thirds miles of old MacAdam pavements and

replaced them with stone or wood blocks.

Most of this work has been done on streets in the business part of the city. The work projected for next year will probably increase our mileage of paved streets by eight or ten miles, although as the initiative of this matter must in every case be taken by the owners of property on the streets, it is difficult to predict what the extent of work will be.

Excavations in newly paved streets have been carefully attended to with the object of preventing this prolific source of destruction to pavements. Permits are only given to parties who have obtained a proper license after filing a bond of $1,000 and depositing $25 in cash with the city treasurer, subject to the order of the city engineer. The conditions I have required of all parties who desire to make excavations in paved streets for gas, water and sewer connections, provide that the trenches shall be refilled with small broken stones, mixed with only a moderate proportion of clay, put in and thoroughly rammed in twelve inch layers. The sides of the excavation at the top are sloped out and double the original thickness of concrete put in, and the blocks replaced in a workmanlike manner. A special inspector is employed for the purpose of securing good work. As a rule, this has been accomplished and the pavement restored to its original condition and without subsequent settlement. This is considered a very important matter, and the requirements are based upon the principle that no individual has the right to dimage a street pavement if it is practicable to prevent it. The Water-Works Company and the Gas Company have a general right to dig up the streets without legal restrictions, which is essentially wrong in principle, but practically, in this city, these companies have usually manifested a disposition to comply with proper requirements.

The general law of the city requires that railroad companies shall pave the space between the rails of all tracks, and a space of eighteen inches on the outside of each rail in the same manner as the roadway outside of such tracks may be paved. Great difficulty has, however, been experienced in getting this work. done right, and practically the paving done by the companies is of a very inferior kind.

A good deal of special argument has been made against the use of concrete on that portion of the street to be paved by the company, as impracticable, but I am of the opinion that it is not quite practicable to use the concrete foundation,