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must be done very promptly in order that the metallurgists may get the results and regulate their processes thereby. The number of chemists is about twenty, and the number of determinations monthly will run somewhere in the neighborhood of 13.000. I think that is all I have to say on the chemical side of the work

Albert Reichmann: I would like to ask the chemist if he thinks he will ever be able to tell the physical quality of steel from the chemical standpoint by chemical experiments. I find that in our reports the chemical tests run very uniform, while the physical tests run the other way.

Mr. Davison: Well, that is taking a rather broad view of the matter, it seems to me. I think it will be universally admitted that the physical qualities of steel are determined largely by the chemical composition at present, although it must be admitted that there are a great many things about steel which are not yet understood. The present development of chemical work in steel is largely of an ultimate nature; that is, we simply determine the percentage of the different elements, and we do not determine the exact condition in which they exist in the steel, that is, the different compounds which they represent, and there is yet a good deal of research work to be done, but the ultimate analysis as at present carried out will give a very close approximation of the physical qualities of the steel. And the irregularities of which the gentleman spoke are not due so much, I think, to the chemical analysis being of little value as they are to heterogeneous structure of the steel, improper heat treatment and the mechanical working of the steel. That plays a larger part in some of these cases than the chemical analysis. If the steel is homogeneous and receives proper treatment, I think the ultimate analysis will enable a metallurgist to tell very easily what the steel will do and what its physical properties will be.

Mr. Stafford: It may be of interest to some of the members here to know that we have just completed the making of plates for one of the largest marine boilers-the largest to go on the lakes. This boiler will be some 14 feet 8 inches in diameter, I think, by 12 feet 8 inches long. The plates are about 11⁄2 inch thick, and the steam pressure will be 200 pounds.

We are also making plates for Cramp, of Philadelphia. The boilers will be about the same size, but I should imagine they will carry steam at some lower pressure, as the guages of the plates are somewhat thinner. I speak of their going to Cramp, because it shows the wide field we are able to supply with plates. They come here because we have the largest mill in the country, and they were unable to get those very large plates elsewhere. These boilers, I think some six in number, involved about 200 tons of steel plate.

The Chair: Can you give us any information about armor plates?

Mr. Stafford: I do not know anything about it. This new plant will be able to turn out these plates about 72 inches wide, but

that of course is very small work compared with the armor plate proper. That of course takes a special plant and apparatus, which we may have some day.

Prof. A. M. Feldman: I would like to ask regarding the structure of the solids which are shown in the photographs, whether you can give any information as to what are the spots on the structure, what do they represent in the ingredients in the hollow parts after they are etched out?

Mr. Davison: The specimens are polished and then etched with either nitric acid or iodine, and the different constituents of the steel are differently attacked by this etching; in that way they are made to stand out and when examined through the microscope are revealed clearly. You might compare the different constituents to the different constituents of a rock, say a granite, for example. The carbon exists in different compounds, according to the amount in the steel and according to the heat treatment that the steel has received. For instance, if you take a carbon steel and quench it above a certain elevated temperature the composition will appear uniform, the carbon will be there in the condition of martensite; if a steel is annealed, or allowed to cool slowly from the initial temperature, the constituents will vary according to the percentage of carbon present in the steel. With a very low carbon the principal constituent will be ferrite, or carbonless iron, and, as the carbon increases, increasing amounts of pearlyte will appear; when the point of saturation is reached, about 80 per cent, varying a little in accordance with the conditions, we find cementite, which is a very hard constituent, that, under the microscope, has a peculiar metallic appearance, being less acted upon by the acid or iodine than the other constituents. In this way we differentiate by the etching these different constituents, and the amount of carbon in any given steel can be approximately told. Not only that, but by the size of the grain and its appearance we can tell what the treatment of the steel has been, whether it has been treated at too high a temperature, whether it has received much working, or whether it is the original ingot metal which has received no working at all.

Prof. Feldman: I would like to ask Mr. Windett whether the gas they produce is cheaper than the naphtha oil, or whatever oil. it is, to use in the open hearth furnaces.

Mr. Windett: We made some investigations of that matter at the time we made the change, and we found that the method of treatment, in view of all the conditions, was satisfactory, so that the practice has been kept up, although should commercial requirements necessitate it, a change from oil gas to producer gas could be made with ease and speed. Metallurgical operations would not suffer by a change of fuel.

Mr. Feldman: Is it cheaper? I know it is more convenient. Mr. Windett: If all the conditions are favorable.

Mr. T. L. Condron: Regarding the slabbing mill, what will be its probable effect upon the physical quality of plates? That is,

what relation will probably exist between the present differences between "front tests" and "back tests" of the same plate as now made, and the differences which may be looked for between tests of top and bottom slabs made from the same ingot after slabbing mill is in operation?

Mr. Stafford: There would probably be more segregation in the larger ingot. By very careful experiments on the small mass of steel I understand that they are able to detect that there is some segregation in all cases. Now with the larger ingot that we produce, there probably would be more segregation, but you have in this large ingot many slabs, that is, you produce many plates, and you would put the upper part in which the segregation would be greatest into a secondary product. The lower part would probably go into the better quality. There is no difference I take it in the amount of segregation-there may be a difference in the amount but it exists in the present form, and will exist when we cast in large ingots. There may not be quite so much variation in a good, small plate as now where it is cast from a small ingot.

Mr. Condron: As I understand, Mr. Stafford, the slabbing will result in a more uniform product of steel in a given area. That is, you can differentiate your steel into different grades better from the large ingots than where smaller ingots are rolled directly into plates? The upper part of the ingot may then be reserved for a different grade of plate, giving you more uniform products. If I understand rightly, by slabbing and separating into first and second-class plate, you will be able to eliminate the segregated part of the ingot from your selected stock.

Mr. Stafford: Yes, I am glad you brought that out. At present, in rolling plates directly from the ingot, we are obliged to throw away the larger portion of that scrap of the plate just on that account, and the larger the ingot the more we are obliged to throw away. Many of you will remember in the Congressional investigation of the navy plates, that Mr. Schwab stated that they were obliged to cut away in that case from 3 to 1⁄2 of the ingot in order to produce slabs, or an armor plate that was free from this segregation. In the same way with rolling smaller ingots, we are obliged to cut off more or less of one in the same degree as is necessary in a large ingot.

Mr. J. C. Bley: I would like to inquire about the number and types of engines that you use.

Mr. Windett: You mean the stationary engines?

Mr. Bley: Yes, the stationary engines, what is the prevailing type?

Mr. Windett: At the blast furnaces, for instance, the blowing engines in use now are simple engines, and condensing; the blowing engines are all vertical, the air cylinder being on the top. That is partly to save floor space. Most of the pumps in the blast furnaces are compound condensing duplex of the Worthington type. In the Bessemer mill, of the blowing engines, two are

of the vertical kind as at the blast furnaces, only they deliver air at 20 to 23 pounds pressure, and two others are horizontal. These are rather old in type and make. It is expected to compound the vertical engines and put on probably some type of condenser. In the rail mill the three principal engines are the engines driving the three rolls. They are all the simple expansion horizontal Porter Allen type. Those are going to be compounded and condensed also.

In addition to that, there are a large number of small engines driving the tables, those are reversing engines; they are either the small Crane type, that is the Crane Manufacturing Co.'s type, or an engine we make ourselves, about 9x16 cylinders, or 8x12.

The engine that runs the hot saws is a Westinghouse simple expansion engine that runs at high speed and drives the saws by belt connection.

The machine shop engine is a compound condensing engine manufactured at the works. In the plate mill the rail train engine is the Porter Allen. In the electric power station plate mill we have one 500 horse-power McIntosh and Seymour engine, and two 250 horse-power compound condensing engines of the Lake Erie Works.

Mr. Bley: In the compounds, are they mostly tandem or cross?

Mr. Windett: All the pumps that are compound are tandems, and the other compound engines are cross-compounds.

Mr. Bley: Do you have many of the Corliss valve gears? Mr. Windett: We have some Corliss valve gears in the engines for blast furnaces 1-4. In compounding the blast furnace engines we expect to displace the present valve gear and may introduce the Corliss. The compounding will require the displacement of the present cylinder, the adopting of a new high pressure and a new low pressure cylinder. The plans for this have been drawn up and specifications sent out asking for bids. That is about as far as we have got on that, but the work is going ahead very quickly. Mr. Bley: I would like to ask if the X-ray has been used for determining the internal structure of large masses of steel?

Mr. Windett: Nothing has been done with the X-ray outside of the hospital work, but we have done more or less work in photographing steel under the microscope. Of course, that simply shows the surface condition.

XXVII.

A VIEW AND DESCRIPTION OF THE BED OF A PREHISTORIC OR GLACIAL LAKE, BETWEEN

SUMMIT AND LAMONT, ILL.

By OSSIAN GUTHRIE-Mem. W. S. E.

Figure 283, on page 681, Volume II, Journal (W.S. E.), shows at section of a bed of a prehistoric or glacial lake, which is fully described in my article on "Relics Turned up in the Drainage Canal," page 472, Volume I, Journal (W. S. E.). On account of this lake occupying the summit of the divide between Lake Michigan and the Mississippi valley, the late Mr. Chas. H. Ford and myself gave it the name of "Summit Lake." The group of boulders in this view (Fig. 283) are some of the glacial implements that carved out this prehistoric or glacial lake, and are here shown just as the glacier left them, approximately, 8,000 years ago. The oval-shaped boulder at the right, in Fig. 283, is the gray granite boulder which now forms the cap-stone of the Marquette Monument at Summit, Illinois, shown in Fig. 277, page 677, Volume II, Journal (W. S. E.). This boulder, which is glacial marked on all sides, may possibly be a native of Hudson's Bay. The bed-rock beneath the mass of drift here as elsewhere throughout the length of the lake is glacial planed, as shown in Fig. 350, herewith.

[graphic]

FIG. 350. Glacial Planed Surface of the Bed Rock underlying the Glacial or

Prehistoric Lake.

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