fact of their being in an inferior degree carbonized-a condition designedly given, because of the toughness required in the peculiar purposes for which these two steels were designed-viz. for springs and saws. 2. Experiments with steel of different denominations, converted out of best Swedish iron, marked hoop-L. V.-Cast Steel: Average Weight, 952 grains. V. VI.-Cast Steel: (2nd Series of the above) 952 grains. VII.-Blister Steel: Average Weight, 982 grains. [Tested under a Power of 51° 23′]. The power, after combination, in this last series, No. vII., being determined under the tension only of six plates, or a deviating power of 51° 23', whereas the series Nos. v. and vi. were tested under a deviating power of 71° 47'; the last column of No. vII., compared proportionally with the former, will be too high. But the means of a more correct comparison is given in a subsequent summary or abstract of these experiments, aided by the application of an uniform test. SECT. II. Of the Magnetical Powers, in combination and separately, of Steel Plates (7·5 inches in length), of SIMILAR DENOMINATION, but of DIFFERENT QUALITIES of the original iron. By this series of experiments, was intended to be compared, the respective capabilities for the magnetic condition, in various measures of combination, of steel of known but different qualities, in respect of the iron out of which it had been made. The magnetical capabilities of cast steel from Swedish iron, marked hoop-L, and also of the peculiar cast steel from best qualities of foreign iron, being given in the last section, the results with the additional kinds examined, require only to be here stated. VIII.-Cast Steel from best Bradford Iron: Average [Tested under a Deviating Power of 49° 45]. IX.-The above re-hardened: the Numbers not correspondent in each Series. [Tested under a Deviating Power of 50° 0′]. Ccf.H. 1 X.-Cast Steel from commonest Foreign Iron: 23456 [Tested at a Deviating Power of 50° 0′]. Mean XI.-The above re-hardened: the Numbers in each XII.-Cast Steel from a good quality of Foreign Iron, but not the best: Weight, 1027 grains. With these several series of cast-steel plates, converted out of three different qualities of iron, are to be associated the series Nos. I., IV., v., and vi. of the foregoing section. The comparative magnetical qualities, separately and in combination, are referred to in the General Results; but it will scarcely escape observation, on the most hasty glance over the tables, what a remarkable superiority of magnetic capacity, in the separate plates, is exhibited in the steel from Bradford iron. In plates or bars of the particular dimensions here made use of-the steel from Bradford iron appears to be decidedly the best, for single plate magnets, which I have tried. But this superiority, as shewn by the result of combination, is evidently to be ascribed in considerable degree, though not entirely, to the insusceptibility of this steel for the extreme hardness of cast steel from the best qualities of foreign iron. The hardness, indeed, approximates that of shear steel from hoop-L iron. Still the capability of combining advantageously to a considerable extent constitutes a satisfactory quality in this steel-though inferior to that of the best description of cast steel. powers The series x. and XI., representing the of steel plates from commonest foreign iron, are very unsatisfactory; the degree of hardness of the different plates being found to be most |