is utilized in propelling the vessel.  In spite of all these improvements I have mentioned, there remains the serious question of defects in the material, due to variety of quality and the extreme care that has to be exercised in all the stages during construction of crank or other shafts built of iron.  Many shafts have given out at sea and been condemned, through no other cause than original defects in their construction and material.

The process of welding and forging a crank shaft of large diameter now is to make it up of so many small pieces, the best shafts being made of what is termed scrap, representing thousands of small pieces of selected iron, such as cuttings of old iron boiler plates, cuttings off forgings, old bolts, horseshoes, angle iron, etc., all welded together, forged into billets, reheated, and rolled into bars.  It is then cut into lengths, piled, and formed into slabs of suitable size for welding up into the shafts.  No doubt this method is preferable to the old method of “fagoting,” so called, as the iron bars were placed side by side, resembling a bundle of fagots of about 18 or 20 inches square.

The result was that while the outside bars would be welded, the inside would be improperly welded, or, the hammer being weak, the blow would be insufficient to secure the proper weld, and it was no uncommon thing for a shaft to break and expose the internal bars, showing them to be quite separate, or only partially united.  This danger has been much lessened in late years by careful selection of the materials, improved methods of cleaning the scrap, better furnaces, the use of the most suitable fuels, and more powerful steam hammers.  Still, with all this care, I think I may say there is not a shaft without flaws or defects, more or less, and when these flaws are situated in line of the greatest strains, and though you may not have a hot bearing, they often extend until the shaft becomes unseaworthy.

[Diagrams shown illustrated the various forms of flaws.] These flaws were not observable when the shafts were new, although carefully inspected.  They gradually increased under strain, came to the outside, and were detected.  Considerable loss fell upon the owners of these vessels, who were in no way to blame; nor could they recover any money from the makers of the shafts, who were alone to blame.  I am pleased to state, and some of the members here present know, that considerable improvement has been effected in the use of better material than iron for crank shafts, by the introduction of a special mild steel, by Messrs. Vickers, Sons & Co., of Sheffield, and that instead of having to record the old familiar defects found in iron shafts, I can safely say no flaws have been observed, when new or during eight years running, and there are now twenty-two shafts of this mild steel in the company’s service.