briquettes, or test pieces for determining the strength of cement, first made their appearance. It was a few years later, however, that the actual determination of the value of Portland cement, as contrasted with natural cement, was finally settled by John Grant, the engineer who had charge of the construction of the London drainage works, and in his two papers published by the British Institute of Civil Engineers, and which formed the first literature on the scientific side of cement testing, he showed conclusively that Portland cement with three parts sand, was practically as strong as Roman cement with one part of sand, and this put Portland cement to the front as a material upon which engineers could rely to the fullest extent.

The commercial introduction of Portland cement in England was soon followed by works in Belguim, Germany and France, many of them being established by associates or relatives of Aspdin and Parker, so that in a very few years after the publication of Grant's paper, the Portland cement industry became a well recognized one, not only in England, but also in the countries of the continent.

In this country the cement industry is contemporaneous with the establishment of the earliest waterways. After the original pioneer had opened roads and in a primitive way had built bridges over the small streams and creeks, commerce required more approved methods of inter-communication for the transportation of heavy freight. This led to the great canal systems, which were the first methods for inter-communication between the Great West and the seaboard. The building of aqueducts, locks and dams for these public works required hydraulic mortars, or cements, and in many of the places where this construction had to be done, limestones were discovered which tested according to the theories of Vicat, Smeaton and Paizley and develop the hydraulic qualities necessary for use in construction under water and were made into natural hydraulic cement. Thus it was that in this country as in England, the natural cement industry preceded the development of the Portland cement industry.

It was in the early part of the nineteenth century that these discoveries were made and between the years 1830 and 1860, cement works were established on the line of the Richmond and Allegheny canal at Balcony Falls-on the Ohio River canal at Louisville, Ky.on the Chesapeake and Ohio canal at Cumberland and Hancock, Md.; on the Erie canal at Howe's Cave-on the line of the Lehigh canal at Siegfried's Bridge, Pa., on the line of the canal system of the Hudson river, at Rondout, and on the line of the Welland canal, at St. Catharines, Canada.

While this development of the natural cement industry was going on in this country, and large amounts were being made and material

of England, as has already been stated, was giving way to the artificial Portland cement. These Portland cements were imported into this country in a very small way in the year 1870, and by reason of their great strength, as well as their adaptability to paving and other important work, their sale began to grow in extent, and American manufacturers and others interested in the development of the natural cement industry commenced to look into the reason why this artificial Portland cement could not be produced in their own country.

Practically the first of these was Mr. David O. Saylor, of Allentown, Pa., who was operating in the early '70's a small natural cement works along the line of the Lehigh canal at Coplay, Lehigh county, Pa., and his early experiences are most interesting. He ascertained, by experimenting, that by burning to incipient vitrification the natural rocks in his quarry, he could make a cement which, at short periods, showed tensile strains equal to the imported Portland cement. He found, however, that this cement, when it was left for a time in briquettes or in work, would crumble away and that this was due to the variation in the raw material of the rocks which he used. By sheer force of his native ability, Mr. Saylor studied out and successfully applied to the Lehigh rocks the prin-ciple that had governed the production of Portland cement in Europe, though he was dealing with a material never before used for the purpose.

He found that it was necessary to grind the raw rocks together to produce a material of uniform analysis, and then that it was necessary to make these rocks into bricks or blocks of homogenous character before placing them in the kilns for calcination. This process is still used in some of the largest works in the Lehigh district.

Mr. Saylor's work was materially aided by Mr. John W. Eckert, graduate of the Lehigh University, who became first the chemist and afterwards the superintendent of the Coplay Cement Company, Mr. Saylor's concern at Coplay Station, which he subsequently left to join in the establishment of the American Cement Company, which had been established by Mr. Robert W. Lesley, who had also been connected with Mr. Saylor.

While this experiment was being carried on to success in the Lehigh region, and the foundations were being laid for the large industry that now exists, a small works was erected near Kalamazoo, Mich., in 1872. Owing to the character of the material and the high cost of labor and fuel, this works made cement which was too expensive commercially and did not succeed. Early in 1875, works were started by Mr. W. P. Shinn, in Lawrence county, Pa., at Wampum, using limestone and clay. These works, now owned by the Na

capacity. At South Bend, Ind., Thomas Millen, an Englishman, found a white marl and blue clay which resembled, in composition though not quite in form, the materials used for cement making in England. He started a small works there in 1877, and the plant is still running, though in a moderate way. Mr. Millen later transferred his field of operations to New York State, where he has large works. The Rockland, Me., lime is well known as one of the best and purest in the country, and it was but natural that the Portland cement industry should seek a lodgment in that field. The Cobb Lime Company, an important concern, there started works in 1879, but the product was too dear for commercial success and they were closed down. For similar causes a like fate overtook the National Cement Company, which was established by Mr. S. D. Coykendall and others on the Hudson, in the well-known naturaì Rosendale natural cement district. Thus, it may be seen that out of six original works started in this country prior to 1881, three were failures and certainly the industry, with this percentage of loss, did not offer very encouraging outlook to the investor. At this period, the foreign Portland cement had the market exclusively, and there seemed little likelihood of growth for the American industry.

Patents were necessary to enlist capital in the early enterprises and many of the earlier works were founded on them. The great difficulty in all the American enterprises seemed to be the cost of getting the raw material into powder, then into paste, then into bricks or blocks and then into the kiln with a sufficient economy. About 1884 and 1885 patents were taken out by Messrs. James M. Willcox, E. J. DeSmedt and Robert W. Lesley for the purpose of mixing liquid hydro-carbons with the paste. In this way "a slurry" was made, which, when compressed into balls or eggs could be at once put into the kiln, and thus many of the intermediate steps of drying, etc., were dispensed with, and much labor and money saved. These processes, which were used in the works started by the American Cement Company, at Egypt, Lehigh county, Pa., were based upon the use of the by-products of the manufacture of coal gas, but with the introduction of water gas and the consequent advance in the price of coal tar, the processes were abandoned and other methods adopted. While these methods of saving the intermediate process of drying were being used, other inventions by Mathey, Navarro and Ransome in the same direction gave rise to the establishment of the Atlas Portland Cement Company, which has two large works in the Lehigh region and is another large producer of cement. These processes, based originally on the