294 Chronicles of Science. [ April, 
well, as being the inventor of the so-called “ built-up guns,” and for 
which the Academy awarded him their Rumford medal. 
Professor Gray quotes Professor Treadwell’s own language: 
he says, “ Between 1841 and 1845 I made upwards of twenty 
cannon of this material (wrought iron). ‘They were all made up of 
rings, or short hollow cylinders, welded together endwise ; each ring 
was made of bars wound upon an arbor spirally, like winding a 
ribbon upon a block, and, being welded and shaped in dies, were 
joined endwise when in the furnace, at a welding heat, and after- 
wards pressed together in a mould by a hydrostatic press of 
1,000 tons force.” This and sundry other matters bearing on this 
question are stated to have been published in 1845, and that a 
French translation of the pamphlet was published in Paris in 1848 
by a Professor in the School of Artillery at Vincennes. 
We feel assured that Sir William Armstrong will not dispute 
Professor Treadwell’s claim. The manufacture of “ built-up guns” 
is very much older than the American Professor. We have in 
Edinburgh ‘ Mons Meg” as an example, and similar guns which 
were used at the siege of Calais are still preserved, and gun-barrels 
have long been made in this way. Professor Asa Gray repeatedly 
contrasts Professor Treadwell’s gun with Sir William Armstrong’s, 
failing, apparently, to see that the “coiled cylinders” are only a 
part, anda very small part, of the arrangements adopted in the con- 
struction of the Armstrong gun. No doubt Professor Treadwell’s 
euns are of a high character, and he fully deserves the encomiums 
passed upon him on the delivery of the medal. 
Mr. Mosheimer, who was for a long time connected with the 
gold mines in North Wales, is now engaged in experiments with 
the sodium process of Mr. Crookes in California. He gives the 
following statement of the results of his experiments :—“ I worked 
the same ore, side by side, with the same machinery, and the results 
were as follows :—First lot of 500 Ibs. Each pan with sodium 
yielded 85 per cent. of the assay; without sodium the yield was 
only 55 per cent. Second lot —different ore—with sodium, 80 per 
cent.; without sodium, 60 per cent. Third lot—different ore— 
with sodium, 78 per cent.; without sodium, 60 per cent.” We 
make no comment on these results. 
Mr. E. H. Newby, of London, has patented a process for increas- 
ing the strength of iron, and rendermg it less hable to corrosion. 
It is, at all events, curious enough to be recorded, whatever may be 
its value. Twenty-five pounds of zinc, two-and-a-half pounds of 
tin, five pounds of copper, and one-fifth of a pound of aluminium, 
with two pounds of borax, and one pound of the permanganate of 
potash, are first melted together ; then a thousand pounds of “ white 
iron” are gradually added, and the whole incorporated. The result- 
ing iron is said to be “very strong and pliable, and httle liable to 
