Picton to Whitby giving access to the Durham coal-field. The stone is also largely worked along the sea coast from Whitby to Redcar, and is shipped chiefly to the iron-works on the Tyne.

The Rosedale iron-stone is the richest of all the Cleveland ores. Its colour is dark olive-green, it has a high specific gravity, is compact, magnetic, and polar. It contains from 35.94 to 49 17 per cent. of metallic iron, and is smelted by itself at Ferry Hill, but is chiefly used for mixing with the other ore in the Cleveland furnaces. In 1864, nearly 300,000 tons were quarried and carried to market by a special branch railway. Continuing the survey southward, we find the iron-stone of the Lias cropping out in the direction of Northallerton and Thirsk, and trending thence in a south-easterly course by Easingwold, Hulton, and Market Weighton to the Humber. The dip is here a little north of east, and there are extensive tracts where it has not as yet been opened out.

On crossing the Humber and entering Lincolnshire, we again get on the track of the same bed at Saint Hope and Frodingham, in the northern part of the county, and from thence we can trace it southwards along a low range of hills rising to the eastward of the valley of the Trent. At the Frodingham iron-furnaces, built on the outcrop of the iron-stone, which is here twelve feet thick, there is a very fine section in the railway cutting, which fully exposes the relations of the iron-stone to the underlying Lias. At the Trent Iron-works there are three furnaces, and here the rock is actually twenty-nine feet in thickness! Further south, where the North Lincolnshire Company are erecting two very large furnaces, the rock is of similar thickness.

The mode of working in this district is very simple, and has been described to the writer by Mr. W. Brockbank, F.G.S., as follows:-As the iron-stone lies exposed on the upper surface of the hills, the furnaces are erected upon it as a foundation, and the inclines for raising the minerals to the tops of the furnace are carried down to the base of the iron-stone, where the wagons are filled and hoisted directly to the surface for calcining. As the workings progress, the hollows are partially filled with slag, and the soil is replaced, so that the land becomes fit for agricultural purposes or planting, and is not disfigured by the hideous mounds of clay and refuse, such as are to be seen in many of the older iron districts.

The iron production in Lincolnshire is only as yet in its infancy, about 30,000 tons being the quantity smelted during the past year; but there can be no doubt but that the trade is destined largely to increase. In the first place, the metal produced is of a quality superior to that of the Cleveland district, which is owing probably to the presence of oxide of manganese largely in the rocks, and its more calcareous nature. Some beautiful specimens of

specular pig-iron have been produced at the Frodingham furnaces. The district is also favourably placed with reference to its geographical position: its distance from the Yorkshire coal-field is small, so that while it is within easy reach of fuel, it can send large quantities of the ore into the Yorkshire coal-field for mixing with the argillaceous iron-stone, and this is now practised to a large extent. For shipment it is being placed, by the construction of new lines, in communication with the ports of Goole and Grimsby, while it is also favourably situated for sending supplies into Staffordshire and other inland markets. The metal possesses the qualities of extreme fluidity when melted, and is tenacious in a manufactured state; so that it answers well for hoops and boiler-plates. For general purposes, however, it is improved by the mixture of either Cleveland or hæmatite pig-iron.

The Middle Lias of Northamptonshire has not as yet (as far, at least, as I am aware) yielded iron-stone. The formation is doubtless there, lying about 120 feet under the Northamptonshire iron-stone, which, as already stated, occurs at the base of the Great Oolite. The richness and abundance of this latter ore have probably diverted attention from the former, for it ought not to be forgotten that these Jurassic ores do not force themselves on men's attention, but have rather to be sought for. As I have already described the oolitic iron-stone of this county, I shall therefore pass on to the consideration of the Oxfordshire iron-stone, at the southern extremity of our district.

The iron-field extends over a hilly tract of ground, extending from Edge Hill, near Banbury, on the north, to the valley of the Evenlode, near Charlbury, on the south, near which place it has as yet alone been worked. The ore belongs to the Middle Lias, and is similar in appearance to the Lincolnshire, and sometimes to the Cleveland stone. It consists of olive-green oolitic rock, more or less calcareous, and weathering rusty-brown. At Fawler the thickness is twelve or fifteen feet, and this may be taken as the average over that part of the field where the iron-stone is richest. Towards the western escarpment of the hills, overlooking the vale of Moreton, the rock decreases both in thickness and quality as an iron-stone; as it does also to the eastward, along the valley of the Cherwell, as far south at least as Aynho. Around Bloxham, Deddington, Great Tew, Hook Norton, and Swalcliffe, it appears to be of good quality, and generally forms nearly level terraces, intersected by narrow valleys-a position peculiarly adapted for economical working and drainage. New lines of railway are now being constructed across the richest portion of the district, placing it within reach of South Wales and South Staffordshire; and,

*At Fawler quarries, the yield of which, in 1861, was 6,666 tons. The ironstone has also been worked at Steeple Aston.

judging from the experience of Northamptonshire and the adjoining county, it seems probable that a few years hence furnaces will be erected in this district. The quality of the pig-iron produced, as tested by the trials from the Fawler quarries, has been pronounced good, though the yield is variable, as the rock is often superabundantly calcareous, and the average yield of metallic iron will probably not be found to exceed thirty per cent.; on the other hand, it will require little or no admixture of limestone for fluxing.

The rapid increase of iron-smelting in the new districts may be judged by the following statement :-We learn from the Mineral Statistics of Great Britain,' compiled by Mr. R. Hunt, F.R.S., that in 1864 the total quantity of pig-iron smelted in the United Kingdom was 4,767,951 tons, from 10,064,890 tons of ore. Of this, the North Riding, Lincolnshire, and Northamptonshire produced 431,929 tons. What the total produce for 1865 may be we are not yet informed, as the statistics for this year have not yet been published; but we shall probably not be far wrong if we estimate it at 6,000,000 tons of pig-iron, of which the Cleveland district, Lincolnshire, and Northamptonshire will have yielded 1,100,000 tons. The proportions therefore of the yield from the New Fields to that of the United Kingdom will have been, in 1864, nearly one-tenth, while in the following year it will have been more than one-sixth of the whole. Considering the rapidity with which new furnaces are being erected in these districts, I shall not be surprised if it should turn out that in the present year the proportion will be one-fourth of the produce of the entire kingdom, and this is exclusive of the large quantities of iron smelted from ores sent into other iron districts.

We have now completed our survey of the New Iron-fields of England through a tract of country ranging from north to south for a distance of 200 miles. The survey might be still further extended if we included the Wiltshire ores, which are of limited extent, and belong to a still higher geological horizon. Enough has probably been stated to show the enormous extent of our resources in this mineral, which is sufficiently abundant to use up the whole of our available coal for its conversion into metallic iron. As regards the quality of the iron produced, it is confessedly inferior to that derived from the clay iron-stones and black bands of the coal measures, still more to that from the hæmatites of Ulverstone and Furness; but for ordinary purposes and for mixing with the finer classes, it is of great value. It is, moreover, supplying the enormous demand of the present generation; and, looking to the future, there can be no question that the Middlesborough district is destined to have no rival in any part of the world.