44 ANNUAL OF SCIENTIFIC DISCOVERY. 



as is not unfrequentlj the ease at iron works, it is no longer available 

 for manufacturing purposes. 



The remedy which Mr. Damsel proposed for this prevailing tendency 

 to laminate, consequent on the disposition of the plates or bars in par- 

 allel layers, was to withdraw a few of the long bars, which ran the 

 whole length of the pile, and replace them with a number of short ones, 

 which were to be laid crosswise to the others, and whose length would 

 consequently be equal to the breadth of the pile. The first piles con- 

 structed on this plan were wholly composed of puddled iron disposed in 

 parallel layers, with the exception of the two upper layers, which were 

 of the best metal. The top layer of best metal was of the usual length, 

 and was placed along the pile in the usual manner ; but the one under 

 it, resting on the puddling bars, was composed of short pieces laid across 

 the pile, with their fibres at right angles with that of the others. 

 Apparently, this simple alteration in the disposition of the bars of 

 metal composing the un wrought pile, could not affect the structural 

 arrangement of the manufactured bar, but in reality it occasioned a 

 most important change. The rails rolled from these piles were placed 

 on cast-iron blocks, standing three feet apart, and broken by blows from 

 a heavy ram falling freely between fixed guides. The appearance pre- 

 sented by the fractured ends was very different from anything pre- 

 viously observed in rails. For a depth of full half an inch from the 

 surface, the fractured metal presented the crystalline appearance of fine 

 white cast-iron, while the remainder of the rail exhibited the usual 

 coarse fibrous character commonly observed in rail-iron. Yet, although 

 the contrast between the two metals was striking in the extreme, the 

 line of junction was not discernible, and the union of the two qualities 

 appeared to have been effected in the most solid manner. 



The alteration thus eflected in the structure of the metal, by the sin- 

 gle layer laid across the pile, led to further experiments on piles with 

 two cross-laid layers, having a thickness of long bars between them ; 

 and in subsequent experiments the number was increased, till every 

 alternate layer was thus disposed. The effect of a second cross layer 

 of best iron was to double the depth of the fine crystalline metal , but 

 when this second layer Avas of puddled iron, the metal, when broken, 

 appeared to be formed of large crystals, not unlike coarse white pig 

 iron. The metal in the bars rolled from piles built up with layers laid 

 alternately along and across the pile, could scarcely be distinguished in 

 its appearances from cast metal, so great had been the change which 

 the altered mode of piling had effected in the structural arrangement 

 of the iron. By placing a cross layer of short bars at the head and 

 foot of the pile, the rail, when broken, exhibited the crystalline structure 

 at the top and bottom, with a centre mass of fibrous metal, and on 

 placing cross layers in the middle of the pile only, the rail was found 

 fibrous at both top and bottom, but crystalline in the middle. It is 

 possible, therefore, to produce rails with non-fibrous metal in any de- 

 sired proportion, and occupying any desired position. 



The experiments on the conversion of fibrous into crystalline iron at 

 pleasure, by merely altering the sj'steni of the piling, satisfactorily 

 demonstrated that by disposing a moiety of the bars across, instead of 



