In an interview with Mr. Murdock of the National Vulcanite Company, the offices of which are in the Mills building, New York, a representative of this journal learned some interesting particulars relating to vulcanite pavement.
Vulcanite pavement, said Mr. Murdock, is not a new material, as some people erroneously think. Instead of being new, it is really an old pavement, having been laid as far back as seventeen years ago in the city of Washington, and as a proof of its durability some of this pavement is in as good condition to-day as when it was laid. This is also the case in Pittsburgh, Pa., where vulcanite pavement has stood the severest tests from heavy traffic and with comparatively little deterioration. On the other hand, while asphalt pavement was not laid in any quantities until 1883, 1884 and 1885, it is a new material, and, so far, reports received from places where it is laid go to show that it requires constant repairs. To give an example of the vulcanite’s durability, we have only to cite K street, Washington, where the pavement is almost in as good condition as when it was laid fourteen years ago, the cost for repairs not exceeding four mills per square yard per annum. Then there is L street in the same city, with nearly 25,000 square yards laid in 1887, and all that has been expended upon it for repairs to date is $281. The engineer commissioner in his report for this year states the life of the vulcanite pavement to be fifteen years, and when resurfaced its lease of life is extended for a similar period. Thus with one resurfacing o! this pavement it will last thirty years. The engineer also states another important fact, that vulcanite can be laid from gutter to gutter without fear of rotting, and that it is not so subject to cracks or waves at the surface as asphalt. Such an opinion from such an authority must be admitted as pretty conclusive in favor of vulcanite.
Many of our pavements in Washington were originally laid with only one and one and onehalf inches depth of wearing surface, but we intend to put down no pavement in future with less than a two-inch surface, which will add considerably to its durability’. As to asphalt pavement, it has been found to be subject to surface cracks, to waves and to rot. The latter invariably begins in the gutters when the grade is at all level. In all depressed parts of the surface, where it is likely to hold water underneath the wearing surface, and where it comes in contact with the hydraulic cement space, it at once rots and soon disintegrates. The cause of this is supposed to be that in the composition of the surface material but a very small portion of what is called pure Trinidad asphaltum is used, or, for that matter, sometimes any asphaltum at all.
It has been discovered by an analysis made by Professor J. B. Harrison, the government chemist at Barbadoes, West Indies, that what is termed refined Trinidad asphaltum consists of nearly seventy-eight per cent of organic, mineral and other substances, and only about twenty-two per cent of pure asphalt. Another cause of the disintegration is found in the still bottoms or residuum of petroleum used in preparing the asphaltum lor paving purposes. These still bottoms contain the refuse matter left after distillations of petroleum, and it always varies in the proportion of pitchy, waxy material which constitutes the only quality of cement which it possesses.
The experience of most of the Northern cities begins to demonstrate that pure Trinidad asphalt pavement cannot be laid with any certainty of result. Take, for instance, the cities of Buffalo, St. Louis and others, where this pavement is found to be in a process of rapid decay requiring constant repair, with only a record of two or three years life.
Now, let us analyze vulcanite pavement. It possesses the important quality of being homogeneous in all its parts. It consists of a base of broken stone, bonded together by distillate and rolled by a heavy steam roller until it is compacted together into a solid mass. Upon this base of varying thickness is laid what is called a binder course, consisting of very small broken stone cemented together by the asphaltum distillate mixture. This is also rolled down upon the base by a heavy steam roller, so that the base and binder unite and the top presents a level surface perfectly parallel to the grade of the pavement when finished.
The wearing or top surface consists of stone dust, carbonate of lime, pure silicate, hydraulic cement, flour of sulphur, refined asphaltum and distillate of coal tar in certain definite and fixed proportions. These form a compound substance which has been demonstrated by years of experience and wear to constitute a durable and comparatively smooth surface. When rolled and compacted it presents two inches of wearing surface to travel. Thus it will be seen that we are not claiming too much for vulcanite when we positively state its qualities to be :
Cheapness ; having a better record than any other asphalt pavement; indestructibility and, being homogeneous, with sufficient elasticity ; being impervious to water; retaining its normal condition under any range of temperature known m our latitude; its non-liability to cracking and the consequent rotting of the wearing surface ; minimum of time, labor and expense to keep clean, and its lack of odor. It can be opened and repaired at small cost ; it is free from ” waves ” and “ blisters,” so often seen in asphalt pavements ; after being used for fifteen or twenty years it can be re-surfaced at a small cost, when it beeomesas good a pavement in all respects as when, first laid. In fact, we maintain that vulcanite pavement possesses the five essentials of a good pavement—sightliness, healthfulness, cleanliness, noiselessness and durability.
Now, take Washington, which only seventeen years ago was a very disagreeable place in winter on account of its streets, and what do we find ? It is to-day one of the best patronized cities in the Union owing to the vast improvement in its thoroughfares. This city has been the experimental ground for all asphaltic pavements. Of those laid from 1871 to 1875, the vulcanite comes out at the head of the list, as the following extract from the annual report of the commissioners of the District of Columbia for 1887, giving the cost of maintenance of this pavement for fourteen years, shows : “The 158,595 square yards of vulcanite pavements have only averaged 2.9 cents per square yard per annum for fourteen years’ maintenance, the average being 0.3 cents per square yard for the first five years, 4.2 cents for the second five years, and 4 cents for the last four years. Had all of these pavements been resurfaced during the past year at the contract price of $1.05 per square yard, they would be under guaranty for five years, from July 1, 1887, and the mean annual average expense to the District for maintenance, for a period of twenty years, would not exceed seven and one-half cents per square yard.”
The reason this pavement has not been more extensively laid was owing to a monopoly controlling the asphalt market from 1876 to 1885, which made it difficult to procure asphalt for its construction. In 1885, however, the Congress of the United States virtually ordered the use of vulcanite by the insertion of the following clause in the government specifications : “ Such pavements shall be equal in all respects to the pavement laid on K street, from Ninth to Eighteenth streets.” This was the vulcanite pavement laid by Dr. Filbert in 1874.
The history of the pavement in Philadelphia, Pittsburgh and Baltimore is an endorsement of its excellence. The report of the committee of the common council of the city of Buffalo states that the pavement is rolled with a ten-ton roller, which is double the weight of that used in laying sheet asphalt pavements, thus absolutely insuring a sound foundation. The pavement, while a solid mass, has sufficient elasticity to furnish a good footing for horses, the wearing surface being granular and not slippery, as in other pavements of this character.
The illustration given herewith will show the proportions relatively of the materials used in constructing the vulcanite.
It should be mentioned that the National Vulcanite Company was recently organized under the laws of the State of New Jersey, and is composed of citizens of good social and commercial standing, the present officers being, president, George V. Quintard ; first vice-president, David L. Bartlett ; second vice-president, DeWitt C. Cregier ; third vice-ptesident, Louis S. Filbert; secretary and treasurer, L. H. Stevens. The company has a long list of testimonials from officials and committees where the vulcanite has been laid, from which it can be seen that the unanimous opinion appears to be that it is a much superior pavement to any others of the kind. Those intending laying pavements will find it most advantageous to write the company for information before letting contracts. The office is at 15 Bread street, New York.
BOURNEMOUTH’S SAT.T WATER System.—The town of Bounemouth, Eng., on May 15, put in operation its new works for the distribution of salt water for municipal purposes. The works consist of two brick water-towers, with cast-iron tanks, having a capacity of 25,000 gallons each, having a total height of fifty-eight and fifty-five feet respectively, the level at the lop of the tank being 188 feet above sea-level, and about a mile distant from the sea; together with fifty-seven hydrants, fifty-seven water-posts and eighty sluicevalves. There are about six and one-half miles of six-inch pipe, about seven miles of four-inch pipe and about 390 yards of eight-inch suction pipe. The total cost of the work was about £qooo, and they have a pumping capacity of 100,000 gallons per day. It is estimated that the cost per 1000 gallons will be about three pence.