SCIENTIFIC SUMMAEY. 
125 
the pre^dous castings had been made. In the centre of the floor a great pit 
was dug, and in this the mould Avas framed, the anvil being cast with its face 
downwards. The iiioidd was tweh^e feet square at the base, 1 1 feet 6 inches 
deep, and was calculated to contain nearly 170 tons of iron, when full. At 
interA’’als outside the shop were five furnaces, and at six o’clock in the 
morning these began to pour their molten contents into a huge chasm, and 
continued till about five o’clock, when the operation was declared to be 
successfully completed. The scene in the casting-shop was a strange one to 
ordinary eyes. From four or five different points, streams of liquid fire were 
slowly flowing towards the edge of the pit, where they fell, amid showers of 
starry sparks, into the A^ast seething mass beneath. A metal rod was thrust 
through the mass to test its perfect liquidity, and this having been satisfac- 
torily proved, the top of the pit Avas carefully closed, to be opened again at 
the expiration of seven Aveeks, the period requisite for the cooling of the 
metal. This monster anAul will have, when completed, to sustain the blows 
of a 25-ton Nasmyth’s steam-hammer, and Avill be employed in forging the 
600 and 300-pounder guns that the Messrs. Firth are manufacturing for Mr. 
WhitAvorth. — Vide Artizan, Sept. 1, 1864. 
The Purification of Plumbago Crucibles is achieved by Mr. T. Vaughan 
Morgan’s method with considerable ease. The plumbago, in its impure con- 
dition, is brought to a Ioav red heat in an oven or retort, and by this means 
the iron present becomes converted into a magnetic proto-carbide, which can 
then be remoA^edby magnetic or electro-magnetic action. 
Scottish Coal and Iron . — From Mr. W. Moore’s useful paper, lately read 
before the Institution of Mechanical Engineers, we learn the following impor- 
tant particulars : — The valuable seams of the Glasgow coal field are situated 
in the counties of Lanark, Stirling, Dumbarton, Eenfrew, and Linlithgow, and 
lie between the new red sandstone and the Hurlett coal. They are divided 
into upper and lower series of minerals. Those seams lying above the 
Garnkirk limestone form the upper series, and those beneath the Fossil lime- 
stone form the lower series. It is from the upper series that the coals have 
been taken for the supply of household, manufacturing, and iron-smelting 
purposes, during almost the whole history of the coal fields ; and the upper 
seams in this series are collectively knoAvn as the Glasgow and Monkland 
seams, extending over an area of about 37 square miles, more or less inter- 
rupted by faults. There are .also several minor seams of coal in the upper 
series, which are, however, mainly local, and worked only in the special 
districts in Avhich they are found. The main supply of iron for the use of the 
Scotch iron-works conies from the two Fossil ironstones, the two Garscadden 
blackband ironstones, and the Faisley ironstone. The whole Glasgow mining 
district contains 111 blast-furnaces, which produce 900,000 of pig-iron per 
annum, and consume about 2,500,000 tons of coal, 1,134,000 tons of iron- 
stone, and 445,000 tons of limestone. The entire district contains about 260 
collieries, which raise annually about 8,500,000 tons of coal, or nearly 77 per 
cent, of the whole produce of Scotland. 
The Neio Baschette Blast Furnace . — A novel form of blast furnace is the 
invention of a native of St. Fetersburg, named Kaschette. It consists first of 
a blast furnace, the hearth of Avhich, when bisected by a horizontal plane, 
presents a narroAv, long rectangle, the tAvo short sides of Avhich are to be used 
