On the top of the half octagon of the handrailing is placed an ornamental lamp post with five lights.

These bridges are effectively ornamented by artistically sculptured stone lions resting on heavy pedestals.

So far the bridges are finished, but they will be greatly improved in appearance by placing the ornamental posts and chains. between the open space left, as can be seen on my first design. I have no doubt that as soon as the ground is properly graded and sodded around these bridges that they will make a very noble and elegant appearance.

The ornamental lions for this bridge were donated by Mr. H. C. Payne of Milwaukee and sculptured by Mr. Paul Kupper of Milwaukee.

In order not to make my paper too long and wearisome, I will close with a few remarks as to the conditions under which an engineer who has a desire to develop the artistic side of his profession has to struggle. In the first place, it is a great pity that the public in general takes so very little interest when the question of embellishing a city or park arises. If the people could be awakened to appreciate more fully what the conditions really are, it would be much easier for the professional man to develop this special branch of engineering. Even architects are confronted with so much ignorance on the part of the public that they are greatly hampered in carrying out their artistic ideas. This is more the case with the engineer, of whom seldom anyone expects more than his name indicates. It, therefore, gives us a great deal of joy when we meet among unprofessional men one who understands our artistic aim, and whose judgment is guided by rich experience gathered through traveling all over the globe. Such a man was the President of the Park Commissioners.

Let us hope that people will become better acquainted with the rich treasures of art in this beautiful world, so that engineers and architects will always receive the fullest support in carrying out their artistic ideas.

DISCUSSION.

A Member: I would like to ask Mr. Sanne about the color of the iron work of the bridges.

Mr. Sanne: The color of the bridges is black (graphite paint) which is very effective. We give the whole bridge one coat of black, the ornamental casting standing out very clearly.

When I made the designs of these castings, they were simply for cast iron plate with regular diamond face, and when I went to the shop the patterns were not diamond faced, but something similar, and I was foolish enough to allow them to use them. I regret this very much, because the effect of these bridges. would have been much greater if it had been made as I had designed.

Mr. W. H. Finley: I would ask why you use cast iron at all? Mr. Sanne: In the first place, when I designed these bridges I started with open spandrels and wanted to build up a sort of a post, so as to get a most pleasing effect for the rail. I wanted to have castings to show a support for my railing, and also a support for the column and arch; that would have been all right. I could have done away with the rest of the castings, but the trouble here was a big flue resting on the arch-rail that would have been very ugly. I do not consider the castings first-class myself; the thought came too late after the material was ordered and all the patterns made. I will tell you one thing-it has been suggested that I was wrong in leaving out the sway rods and lateral trussing, but I made it this way: Where the post strikes I have a very heavy strut made out of 21⁄2" by 21⁄2" angles, and connected these struts to each rib by double truss plates, and it makes it appear from below like the ceiling of a room, with ornamental panels. I was under the bridge when a big wagon went over rapidly. I was holding on to a truss and did not feel the least bit of jar. That shows that the construction is strong.

Mr. Finley: I saw those bridges Sunday, and they make a very pleasing appearance. To go back to the ornamentation, Mr. Sanne has designated a cast plate that gives the appearance of a keystone in a stone arch. I think that detracts very much from the appearance.

Mr. Sanne: To be honest about it, I pitied myself that I did it, but it is too late now. I thought really by doing that I would make it more interesting, that was the main idea. This whole ornamentation does not figure so much in any structural way, you might say. I should have left that keystone out entirely.

Written discussion by RALPH MADJESKI, M. W. S. E.

In his very interesting paper Mr. Sanne justly points out the increasing necessity for the engineers to study the aesthetic side of structures especially in more populated districts. There seems to be a prevalent idea among even some of the best engineers of our country that the addition of a few cast iron stars, bent bars, perforated plates in the portals or corkscrews on the hips will make any bridge look handsome. If the skeleton of the bridge or of any structure is not designed æsthetically, such petty ornaments only make things worse and should always be discouraged. It is impossible to take the skeleton of a hunchback and make an Apollo of him by covering it with any amount of beautiful flesh and skin. If a structure is to be beautiful its æsthetic side must be given equal importance and attention with its stability. Both have to guide the designer from the very conception of the project; the skeleton must be built in harmony with the ornaments.

The criticism raised by Mr. Finley at the meeting regarding the

ornament in the shape of a keystone is, I think, correct. While in a masonry arch a keystone may and often does look very well as being appropriate to that kind of construction, a keystone in a steel arch gives an impression of something superfluous and its omission would have been an improvement. One other thing does not, in my opinion, produce the harmonious effect that it should, and that is the upper portion of the spandrels. The three first panels from the abutments are crowned with a semicircular arch, the fourth panel has only one-half of an arch, and the center panels are rectangular, having no arch at all. The center panels, as a matter of course, do not admit of a semicircular crowning, but it seems to me that the detail could have been arranged so as to present a similarity of panels and avoid the somewhat sudden change of form and the appearance as if something were missing in the panels near the center. Mr. Sanne places his outside arched ribs under the railing. This is right, but is not always done. I have seen arch bridges with sidewalks placed on projecting brackets, overshadowing elaborate arched ribs. This Mr. Sanne has very wisely avoided. This idea in leaving the braces between spandrel posts and arches as open as possible is a very good one.

XLII.

A COMPARISON OF THE HOLLOW BORED METHOD AND THE FLUID COMPRESSION HOLLOW FORGED

METHOD OF MAKING STEEL FORGINGS.

By GEO. H. BRYANT, Assoc. M. W. S. E.

In presenting this paper before your society it is not my intention to deal in detail with the many processes of manufacturing hollow bored shafts and steel forgings, as the various methods have previously been extensively presented and discussed.

Some of the papers, however, I believe, have laid too great a stress upon certain processes that are more to the advantage and benefit of the producer than to an increase in the merit of the finished material produced, and it is my intention to show why the Krupp Works, after having experimented with the different processes, adhere to their present method.

The process that has been most thoroughly and elaborately submitted is undoubtedly that used to produce fluid compressed steel, and the Krupp Works a number of years ago made extensive and careful experiments with this method of making ingots. for heavy forgings, and it is a noticeable fact that today they are using their method of casting a larger ingot than is cast by other manufacturers, and do not in any way use the fluid compression.

The Krupp ingots, however, are cast three times the diameter of the finished shaft, while the most modern works cast ingots of but twice the diameter the shaft is to finish.

Segregation, of course, takes place in the centre of every ingot, large or small, and as is admitted by the advocates of fluid compression, is not prevented by that process.

Further on I will state how piping is prevented by the Krupp method, but first I will say that a longer section of an ingot can undoubtedly be used for the forging by the steel maker using the fluid compressing process, for the hydraulic pressure must force the gathering air or gas cells higher in the mould than the ordinary static pressure does. This is an economical result, however, of benefit to the manufacturer only, the character of the material in the melting charge and the subsequent forging and treatment being responsible for the character of the finished steel and its merit.

For many years the Krupp Works, and recently most of the works in this country, have used hydraulic forging presses for the manufacture of the largest shafts, as the material can be

thoroughly worked by this process only, being a most important point for the strength of the shafts, and for this purpose the Krupp works at the present time are equipped with a large number of hydraulic presses of different capacities from very small up to those of 5,000 tons effective power.

At the Krupp works, as above stated, the rule observed is that the diameter of the ingot must be three times the diameter of the finished shaft, while it is understood that the most modern works in the United States forge from an ingot but twice the diameter of the finished shaft. By the Krupp rule an ingot is drawn out to the high degree of 9 to 1 as against 4 to 1 by the process employed in this country.

At works which forge hollow, a hole is bored through the ingot of the diameter of the bore of the finished shaft, consequently necessitating the cooling down of the ingot before being forged.

Even if the ingots cool down very slowly, this method nevertheless, involves considerable risks, as the strains which are unavoidably produced in the ingot, in this condition of largely crystalline structure, are likely to cause cracks. The reheating of the ingot is for the same reason unreliable, even if the greatest care be taken.

For these reasons at Krupp's Works all large ingots for shafts and other heavy forgings are never allowed to cool down after casting, nor during the process of their manufacture, but are kept hot until the working of the forgings under the hydraulic presses has been completed.

By working the ingot from its original heat the detrimental effects from piping are removed, as the strains causing piping are not allowed to generate, owing to the working from the hydraulic press both by compression and drawing out.

As to the most important advantage realized by boring out the ingots as done at works which practice forging hollow, is that in this way a part of the casting is removed to which the greater part of the impurities, such as phosphor, sulphur, manganese, etc., have segregated, it needs probably no further explanation that this end is attained much more effectively by Krupp's method in boring out the solid forged shaft, than by the process where the ingot is bored out, before having them forged down, in consequence of which a much smaller percentage of the impure material is bored out.

In the case of the crucible steel employed at Krupp's Works for shafts these segregations are of much less importance than in the case of open hearth steel, which, according to a paper recently read before this society, can be qualified as high grade steel only if it contains not more than .04 of 1 per cent phosphor, sulphur and other impurities, while Krupp's crucible steel contains less than .02 of 1 per cent of phosphor, sulphur, etc.

While some works resort to the fluid compressing process in