JOURNAL

OF THE

ROYAL AGRICULTURAL SOCIETY

OF ENGLAND.

I.-Relations of Geology to Agriculture in North-Eastern America. No. II. By JAMES F. W. JOHNSTON, F.R.S.L. & E., Hon. Member of the Royal Agricultural Society.

III. Relations of Geological Structure to Agricultural Capability in the Province of New Brunswick.-The examples of a close relation between geological structure and agricultural capability, which I introduced into the preceding part of this paper, were interesting to the English reader chiefly in their purely scientific and economical bearings. Referring to the Atlantic border of the United States, and to the interior of the State of New York, they would come home, if I may so express myself, to few among ourselves as a matter of directly personal concern. It will be somewhat different as regards the example I am now about to submit. It is drawn from one of our own British provinces, where many of us have friends and relatives, and where wide unoccupied lands exist, to which we may emigrate without either abandoning our loyalty or giving up our connexion with the homes of our fathers.

The province of New Brunswick contains an area of 18 millions of acres; much of this is still covered with forests, and many districts still unexplored even by the lumberer. As represented in the geological maps hitherto published, its central part forms an extensive coal-field, bounded on the north by a riband of granitic and of old metamorphic and slate rocks, which runs diagonally-or in a north-east and south-west direction-across the whole province. On the south and south-west it is bounded along the shores of the Bay of Fundy by a belt of slate rocks of uncertain age, altered and hardened by extensive masses of hard, intrusive trap, which give an inhospitable and uninviting character to the region over which they extend. This coal-field occupies about one-half of the whole area of New Brunswick; and, as it is situated in the central part of the province, the rocks * See this Journal, vol. xiii. Part I.

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of which it consists impart their prevailing physical characters to the soils of this large portion of the colony.

It may be said with truth that the extensive prevalence of this coal-field in New Brunswick forms alone a striking illustration of the close natural connexion which exists between geological structure and agricultural capability. Of every extensive coalfield this might, to some extent, be said; but there are two circumstances in connexion with the coal measures of New Brunswick, which in an especial manner determine the agricultural relations of the soils which rest upon them.

The first is the chemical nature of the numerous beds of rock of which this coal formation consists. These are, for the most part, grey sandstones, sometimes dark and greenish, and sometimes of a pale-yellow colour. The siliceous matter which they contain is cemented together or mixed with only a small proportion of clay (decayed felspar principally), so that when these rocks crumble, which they readily do, they form light soils, pale in colour, easily worked, little retentive of water, admitting therefore of being ploughed early in spring and late in autumn; but hungry, greedy of manure, liable to be burnt up in droughty summers, and less favourable for the production of successive crops of hay.

Of course, among the vast number of beds of varied thickness which come to the surface in different parts of this large area, there are many to which the above general description will not apply-some which contain more clay and form stiffer soils; and some which, though green or gray internally, weather of a red colour, and form reddish soils: but lightness in texture and in colour forms the distinguishing characteristic of the soils of the whole formation. The generalization drawn from this single fact, therefore, gives us already a clear idea of the prevailing physical character of the soils over a large portion of the province, and illustrates the nature of the broad views which make the possession of geological maps so valuable to the student of general agriculture.

In other countries, as in England and Scotland, the coal measures contain a greater variety of rocks than is found over the carboniferous area of New Brunswick. They are distinguished in our island by the frequent recurrence of beds of darkcoloured shale, often of great thickness, which form cold, stiff, dark-coloured, poor clays, hard to work, and, until thoroughly drained, scarcely-except in rare seasons-remunerating the farmer's labour. Numerous sandstones do indeed occur, producing poor, sandy, and rocky soils; but it is the conjoined presence of the cold clays and the poor sands, which, in the midst of their mineral riches, have caused large portions of the counties of Durham and Northumberland to remain among the

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least-agriculturally advanced and least-productive parts of the low country of Great Britain.

The second circumstance by which the agricultural relations of this portion of New Brunswick are determined, is found in its general physical conformation. It is distinguished by a general flatness of surface: it undulates here and there, indeed, and is intersected by rivers and occasional lakes; but it consists for the most part of table-lands more or less elevated, over which forests, chiefly of pine-timber, extend in every direction. This general flatness is owing to the small inclination of the sandstone strata on which the country rests, and to the small number of striking physical disturbances to which, as a whole, they have been subjected. These level tracts of land are not unfrequently stony, covered with blocks of grey sandstone of various sizes, among which the trees grow luxuriantly, and from among which the settler may reap a first crop of corn, but which almost defy the labour of man to bring the land into a fit condition for the plough. It is chiefly on the borders of the coal-field, however, that these stony tracts occur, as if the disturbances, to which the neighbouring rocks have in many places been subjected, had broken up the edges of the sandstone strata, and scattered their fragments over the adjoining surface.

A characteristic feature which results from this physical flatness is the occurrence of frequent bogs, swamps, carriboo plains, and sandy barrens. The waters which fall in rain or accumulate from the melted snow rest on the flat lands, fill the hollows, and, for want of an outlet, stagnate, causing the growth of mosses and of plants of various other kinds, to which such swampy places are propitious. Thus bogs and barrens, more or less extensive, are produced, and these greatly modify the natural agricultural relations of the surface.

Thus the geological age, the chemical composition, and the physical disposition of this coal region, in reality appear almost equally to conspire in producing the peculiar general agricultural character of the central half of the province of New Brunswick. To this conjoined influence of important modifying causes I shall again advert before the close of the present article.

But New Brunswick also presents examples of the most striking and immediate dependence of agricultural value upon geological structure alone. On the outskirts of the coal-field, and rising up from beneath its edges, appear red sandstones and red conglomerates, associated with limestones, red marls, and gypsum. These give rise to soils of a remarkably fertile character, in the midst generally of scenery of a most picturesque description. In such localities rock and soil so closely accompany each other, that the most sceptical is compelled to admit that the

change in forest trees, in character of soil, and in nature of rock, are at once simultaneous and determined by a common cause.

The following section (No. I.) gives an idea of the way in which these rocks occur in connexion with the coal measures, and of the kind of soils which they respectively form :

The section commences on the left with the trap and altered rocks which bound the coal-field towards the south, as at the head of Belleisle bay, or on the Hammond river, about twenty miles from the town of St. John. On these rocks scanty soils are found, and the gloom of the narrow-leaved forest is rarely broken by the intrusion of the more cheerful beech, the oak, or the maple. But on the rounded hills of the red conglomerate (1),-which in Albert county remind the English traveller of the hills of our own Monmouthshire-broad-leaved forests of various trees cheer the eye, while the free and open soils which rest on them, though sometimes too gravelly, yet admit of being cultivated along steep slopes till the waving corn crowns the very tops of the hills. In the beautiful Sussex valejustly the boast and pride of the province-and in some of its tributary valleys, the eye recognises with pleasure the features, both physical and agricultural, which are familiar in the red sandstone slopes of Strathmore, in the richly-farmed red sandstone fringe of Sutherland, and where a tillage hardly to be surpassed crowns the hills of Wooller, and accompanies the Northumbrian tourist to the foot of the Cheviot hills.

Over the red conglomerate (1) lies the blue limestone (2). On this rock the soil is sometimes thin, and, like our own blue limestones, the rock breaks out in some places into abrupt cliffs and naked slopes. Generally, however, it is covered with soils which are easily brought into culture, and are especially favourable to the growth of wheat. Of the native forest trees of North America, the white