Chapter VII: Geological Notes

In a county like Lincolnshire, mainly agricultural, in which the operations of man are, for the most part, confined to the earth’s crust, in ploughing and sowing, and, as some one has said, in “tickling” the earth’s surface into fertility,—in such a county we are not led ordinarily to explore the inner bowels of the world; as is necessary in mining districts such as certain parts of Yorkshire, Durham, Cornwall and elsewhere. Yet, with regard to our knowledge of its geological features, Woodhall may be said to compare favourably with a large majority of places. With one exception {84a} it is the spot, _par excellence_, in this part of the kingdom, where the earth’s hidden resources have been tapped, and tapped to considerable purpose, in the unique commodity for which it is famed—its mineral water. The book of Nature, so often “sealed,” has here been opened and its contents indexed. We have in the strata of the Woodhall well sundry chapters in the earth’s past history unfolded, at least to the initiated. The writer is not going to attempt here a systematic disquisition on a subject so abstruse (for which, indeed, he is not qualified), beyond touching upon some of its more salient, or more interesting features. The geological records of the Woodhall well have already been given {84b} in the very concise form in which they have been preserved for us. Whether they are to be entirely depended upon is questionable, but we may here repeat them:—Gravel and boulder clay, 10 feet; Kimeridge and Oxford clays, 350; Kellaways rock, blue clays, cornbrash, limestone, great oolite, clay and limestone, upper Estuarine clay, 140; Lincolnshire oolite, and Northampton sand, 140; lias, upper, middle, and lower, 380 feet; total, 1,120 feet. The mineral spring is said to have issued from a stratum of spongy rock lying at a depth of 540ft. {85a} This would probably be in or near the ferruginous Northampton sand, the lowest layer of the oolite, and lying immediately above the upper lias. {85b}

In the year 1897 a boring was commenced within 500 yards of the original well by the artesian engineers, Messrs. Isler and Co., on behalf of the Rev. J. O. Stephens, on the west side of the Stixwould road, with a view to obtaining a second supply of the Woodhall water; this was carried to a depth of 700 feet. The engineers furnished me with a register of the strata so far pierced by the bore, but, as they are not described in the technical terms of geology, it is rather difficult to compare them with those of the old well. At a depth of 490 feet, sandstone with iron pyrites was pierced; this would probably be the ferruginous Northampton sand of the Oolite. It is at a less depth than the same stratum at the Spa well; but that was to be expected, as geologists state that all the geological strata “dip” eastward, and this bore being to the west, the stratum would naturally tilt upward. This born was ultimately abandoned. According to the records of the Spa well, derived from Dr. Snaith, of Horncastle, who knew the well from its birth, the saline spring was found at 540ft.; but Dr. Granville, who visited Woodhall, and wrote his version, in 1841, puts it at 510ft. It is difficult to say which of these two doctors, who differ, should be accepted as the more trustworthy; and in 1841 Dr. Granville would still certainly be able to find plenty of persons familiar with the well and its details. But in the ferruginous sand, or near it, the spring was to be expected; and there it would seem Messrs. Isler, in the new boring, found saline water, though only in small quantity. The depth, according to their computation, was, as we have said 490ft., which is 20ft. above the Spa spring’s level, according to Granville’s version, and 60ft. above the depth given by Snaith. The paucity of the supply of the saline water in the Isler boring may probably be accounted for thus: The trend of the current found in making the Spa well was said to be from south-east to north-west, whereas this new bore is very nearly due west from the Spa well. If, therefore, the stream is of narrow width, this later boring is scarcely in the position to catch more than the side soakage of the current, and it would seem that the main stream can only be tapped either by another boring further north, or by a lateral shaft from the present bore running northward till it encounters the current. There remains, of course, the further and open question as to whether the saline stream formerly passing _through_ the Spa shaft, still continues its former north-westerly course, after having the outlet afforded by that shaft. Would it not be more in accordance with the law of nature that the stream should take the course of least resistance by rising in the well, and not flowing further along the bed of its special original stratum? If that be so, the only chance of another well would be to bore south-eastward of the Spa; and probably the shaft sunk by the late Mr. Blyton beside Coalpit Wood, if it had been continued, would have proved a safer venture than any other as yet attempted. At some future time we may have the wolf disturbing the stream, above the lamb represented by the original well, to the detriment of the latter. It may be here noticed that in the Scarle boring, as we are told, there was found a strong spring in the upper part of the lower Keuper sandstone at the depth of 790ft., and a still stronger spring at the base of that formation at 950ft. In that case, therefore, as also at Woodhall, the water was found in sandstone, but at a much greater depth, and also in sandstone of a different character, viz., the Keuper at Scarle, the Northampton at Woodhall. Another difference is that in the Scarle strata we pass at once from the surface drift to the lower Lias; the Kimeridge clay and all the Oolite formations, which are found at Woodhall, with a thickness of some 630ft., being entirely absent. These differences, of course, illustrate the fact that, owing to abrasion and other causes, not only do the strata underlying the surface drift vary in different localities, but their several thicknesses vary; while, as at Harrogate, the mineral properties of the water also vary at a distance of only a few yards. Pass beyond the limits of the particular stream, and, below ground as well as above it, you are not “in the swim.”

In the spring of 1904, Mr. R. A. Came, of the Royal Hotel, commenced sinking a shaft, in search of the Spa water, at a point some ¾ mile south of the original well; and early in 1905 water was struck at a depth of 492 feet, which proved to have the same saline properties, with the addition of Epsom salt, a good supply issuing from the spongy sandstone. This opens up a vista of great possibilities in the future; it does away with the monopoly hitherto existing, and may have a most important effect, in the further development of the Spa. The well is 7ft. in diameter, is bricked to a depth of 495ft., and sunk to 520ft. The boring was carried out by Mr. Joseph Aldridge, of Measham, near Atherstone, Warwickshire, an expert mining engineer. Many fine fossils, as ammonites, belemnites, and bi-valves, were found in the different strata that were pierced.

I now proceed to remark upon some of the geological strata, as found at Woodhall. And first, after the mere surface gravel, we have the Boulder clay. This has a very interesting history. In the “Life of Nansen,” the Arctic traveller, it is stated {87a} that the geological strata of the Arctic regions show that at some remote period the climatic conditions were the reverse of those which prevail now. Throughout those regions, at present of intense cold, there was quite a southern climate, in which walnut trees, magnolias, vines, etc., flourished; while, on the other hand, there was also a period during which our own country, and large parts of the Continent, lying in the same latitude, were buried under vast ice-fields with an Esquimaux climate. It is there further stated {87b} that boulders are found scattered over Norway, Sweden, and Denmark, which have been transported thither on glaciers, from regions still further north. In like manner glaciers at one time also spread over what are now Scotland and a great part of England, bringing along with them boulders from Norway, and Scandinavia generally. The present condition of Greenland, with its vast glaciers, pouring through its valleys, down to the water’s edge, on the sea shore, illustrates the condition of our own country at that remote period. {88a} As regards this country, these ice-streams may be classed under two distinct heads, (_a_) the native, inland glaciers, and (_b_) the north-eastern, Scandinavian glacier. To speak first of the former. As the climate, from causes into which we cannot here enter, {88b} gradually became coldier, glaciers were formed among the rugged hills in the present lake country of Cumberland and Westmoreland, some of which pushed their way westward, literally inch by inch, until they debouched in the Irish Sea, and filled it to overflowing, for it is only shallow. From Borrowdale, Buttermere, Eskdale, and other head centres, they also streamed southward and eastward. There was an immense central stream, which forced its way over the wild tract of Stainmoor (named doubtless from the thousands of boulders with which it is strewn); then, fed by lateral branches from many directions, it traversed Teesdale, turned towards the coast, passing by Scarborough, and so on to Holderness and the Humber, a branch also filling up Airedale and the Vale of York. {88c} From Holderness it passed the Humber, into Lincolnshire. Its most eastern limb would doubtless have debouched in the North Sea, and filled it; but here the north-eastern glacier, to which I have alluded, came into collision. Taking its rise in Scandinavia, it had spread into a vast sheet in parts 3,000ft. thick, {89a} filled up the shallow North Sea, and the Baltic, a veritable _mer de glace_, and over-run northern Germany, its thickness even at Berlin being supposed to have been 1,300ft. Impinging on our eastern coast of Scotland and of northern England, it spread over a great part of Holderness, meeting and blending with the inland native glacier on the Humber; and the vast united ice-stream thence pursued its onward southern course, enfolding everything in its icy embrace, to the Thames and to the Severn. {89b} These great ice-streams created the geological formation called “The Drift,” or boulder-clay, which we have at Woodhall. The clay is simply the _detritus_, produced by the grinding, through long ages, of the rocks under the vast and weighty ice-fields slowly moving over them, and the abrasion of the hill-sides which they scraped in their course. The boulders are detached fragments, which fell from various rocky heights overhanging the ice-stream, rested on the surface of the ice-sheet, were borne along by it through hundreds of miles, and when, in the course of ages untold, the climate became milder, and the glaciers gradually shrunk and eventually disappeared, these fragments, often bearing the marks of ice-scraping, and oftener rounded by ice-action, fell to the soil beneath, and remain to this day, to bear their silent witness to the course once taken by the giant ice-stream. The period through which this process was going on has been variously computed, from 18,000 years, according to the estimate of Major-General A. W. Drayson, F.R.A.S., who gives elaborate astronomical statistics in support of his views (Trans. Victoria Institute, No. 104, p. 260), to 160,000, as calculated by Mr. James Croll (“Climate and Time”). It is now generally held that there were more than one ice-age, with inter-glacial breaks. These boulders are abundant in our neighbourhood, and of all sizes. They may be measured by inches or by yards. There is a good-sized one in the vicarage garden at Woodhall Spa, which the present writer had carted from Kirkby-lane, a distance of a mile and a half. There is a larger one lying on the moor, near the south-east corner of the Ostler Ground. The writer has one in his own garden, a large one, more than 6ft. in length by 3½ft. high, and 2½ft. thick. It took five horses to drag it from its position, a quarter of a mile distant. There are six visible in the parish of Langton, two or three large ones near Old Woodhall Church; several large ones in Thimbleby, Edlington, and elsewhere. Smaller ones are often to be seen placed at turns in the roads to prevent drivers running their vehicles into the bank, or used as foundations to old cottages or farm buildings; and still smaller specimens may be constantly picked up by the pedestrian, or the sportsman, in his rambles through the fields. Much interest has of late years been taken in these boulders, arising from the distinct classes of glaciers to which I have referred, and the consequent difference between the nature of the boulders, as well as the source from which they have come, according as they belong to the one class or the other; and our Lincolnshire Naturalists’ Union have now a special “boulder committee” engaged in the investigation of this subject.

The late Professor Sedgewick, of Cambridge (whose lectures the writer attended), was the first to notice that along the Holderness shore there were (as he says) “an incredible number of blocks of granite, gneiss, greenstone, mica, etc., etc., resembling specimens derived from various parts of Scandinavia.” {90} These, we now know, were dropped by the great Scandinavian glacier; and, along with the kinds of stone here named, there are also boulders of Rhombporphyry (the “Rhomben porphyry” of Norwegian geologists, from the neighbourhood of Christiana), Augite syenite, and several more, not of British origin. These boulders are now being searched for, and found in our own neighbourhood. On the other hand, there is the different class of boulders which were brought down by the native inland glaciers. These consist largely of igneous kinds. The rugged hills of the Lake district owe their origin to fire; and the boulders which the glaciers have transported correspond. The shap granite, for instance, which is probably one of the commonest of this class, comes from the shap granite bed of Wastdale, in Cumberland. Boulders of this rock, as Mr. Kendall tells us, “passed over Stainmoor in tens of thousands,” {91a} to visit us in Yorkshire and Lincolnshire. Other kinds are Felspar porphyry from Eskdale, in Cumberland, Andesite from Borrowdale, Granophyr from Ennerdale and Buttermere, Quartz, Basalt, and several more from the crystalline formations in the Lake district. Several boulders of these rocks have also been found in our own neighbourhood; and doubtless more remain to reward the explorer. {91b} I have dwelt at some length on this particular formation—the boulder clay—because it is the most ready to hand; it lies on the surface, in many parts around us, within the ken of the ordinary visitor to Woodhall Spa. It may give an additional interest to his rambles in search of health, to know that he may, at any moment, pick up a boulder which has travelled further, and passed through more strange vicissitudes, than he can well have done himself; perhaps, with Shakespeare, to read “Sermons in Stones,” and to moralise on the brevity of human life, with all its ailments, compared with those ages untold, through which the pebble in his hand slowly {91c} travelled on its long, laborious journey, to rest at length as a constituent element of the locality, where he himself is seeking relief and recreation.

To the west of Woodhall Spa, beyond the Stixwould-road, near the vicarage, and northward, the surface sand, in some parts, at the depth of a foot, or slightly more, hardens into an ironstone, so compact that tree roots cannot penetrate it. In root-pruning or manuring apple-trees, I have found the tap-root stunted into a large round knob, further downward growth being prevented by this indurated formation. This oxide of iron also pervades the sandy soil, in parts, to a depth of four or five feet, impregnating the water with ferruginous properties, so that it “ferrs” bottles, or vessels, in which it is allowed to stand for any length of time. In consequence, the water frequently has a dull appearance, although the iron may probably make it a wholesome tonic.

The surface sand, which is of a still lighter character on the moor ground in Woodhall, and in Martin, Roughton, and Kirkby, contiguous to Woodhall, is what is technically called the “Old Blown Sand,” borne by the winds from the whilom salt marshflats of the Witham, when it was much wider than at present, and a tidal arm of the sea. It is comparatively a recent formation, yet abounding in fine particles, or pebbles, of quartz, and other elements of far earlier date; the larger of these are often rounded by tidal action. Below this surface sand we find, in many parts, a blue clay of varying depth. In a pit called Jordan’s pond, in an abandoned brickyard on the east of the road to Stixwould, it is at least 16ft. thick; also, in a large pit in Kirkstead, near Hogwood, some half-mile south-east of the Abbey Inn, which was dug to procure this clay, for “claying” the light super-soil, otherwise almost barren, it is many feet thick. Ammonites and other fossils are plentiful in it, often cemented together with veins of gypsum. Both these pits are mentioned in the Government Geological Survey (pp. 152, 153) of “The country around Lincoln.” Close by the latter pit the writer once found a curious fossil, which was for some time a puzzle to all who saw it. It is now in the British Museum, and was pronounced to be an Echinus crashed into an Ammonite.

The Kimeridge clay, named as the next stratum in the bore of the Woodhall well, crops up first about Halstead Hall in Stixwould, and continues through Woodhall to Horncastle, and so on to Wragby and Market Rasen. It abounds in fossils. Mr. Skertchly {92} found in the first of the pits just named, that this clay was divided into three layers, the upper being a line of Septaria (or nodules) full of serpulæ one foot in depth, then soft dark-blue clay, 6ft.; and below that another course of Septaria; and Professor J. R. Blake records from this pit the following fossils{93a}:—Belemnites nitidus, Ammonites serratus, Rissoa mosensis, Avicula ædiligensis, Cyprina cyreneformis, Ostrea deltoides, Lima ædilignensis, Thracia depressa, Arca, Serpula tetragona. In other pits in the neighbourhood several other fossils have been found. {93b} [For a list of fossils found about Woodhall see Appendix II.] A peculiarity of this stratum is that the upper part of it contains bands of “inflammable shales,” being blue, laminated, bituminous clays, which burn readily. It was the presence of these which has tempted explorers to throw away their money in search of coal; as in the case at Donington on-Bain, where Mr. Bogg drove a bore to the depth of 309ft., but only found clay and thin bands of inflammable schist. {93c} In the case of Woodhall Spa, the money thrown away on one purpose has brought health and wealth to others, from a source then undreamt of in man’s philosophy. We cannot leave the Kimeridge clay without noting that its presence at Woodhall, in the position where it is, as the _first_ geological formation below the surface drift, opens to us a vista—reveals to us a yawning _hiatus_—which embraces a vast expanse of time.

In the normal order of geological strata, the whole series of cretaceous formations have to be passed through before reaching the Oolite formation, of which the Kimeridge clay forms almost the upper layer. But at Woodhall and the surrounding district the whole of this series of rocks and soils is wanting. Their absence is eloquent, and tells a tale of widespread destruction. Standing near the Tower on the Moor we can see in the distance, stretching from north-west to south east, the range of hills called the “Wolds,” which, with a “cap” of marls, or sandy and flinty loams, are composed almost entirely of chalk; from them, near Cawkwell Hill (the hill _par excellence_ of chalk), comes the water supply of Horncastle and Woodhall. They extend for a length of some 45 miles, with a width of some six miles to eight. The actual depth of the chalk is not exactly known, but a boring made through it, near Hull, reached the Oolite beneath at 530ft. We may perhaps, therefore, put the average at 500ft. {94a} Doubtless, at one period, this cretaceous formation extended over the whole tract of country, but southward and westward from the foot of the present wolds it has since been swept away. And this must have taken place before the glacial period, because the glacial boulder clay lies upon the Kimeridge clay, which normally underlies the chalk. Mr. Jukes Brown (“Geological Journal,” No. 162, p. 117) says: “The Boulder clay is bedded against the slope of the chalk, shewing that this escarpment had retired to its present position in pre-glacial times.” By what precise process this was effected must be left to our savants to decide; but the remarkable fact remains, that a solid stratum, or rather series of allied strata, from 500ft. to 1,000ft. in thickness, has, by one process or another, been wiped out of existence, over the large area now coated by the Kimeridge clay. Through ages of enormous length the chalk was forming as the bed of a sea; a deposit consisting of inconceivable myriads of beautiful minute shells, mainly of the foraminifera, which can be detected by the microscope; and its destruction probably occupied as long a period as its formation.

Mr. Jukes Brown, whom I have just quoted, says: “The Wold hills must have been, in some way, exposed to a severe and long-continued detrition, when erosive agencies were very active.” Active, indeed, they must have been, to efface from an area so extensive a solid formation from 500ft. to 1,000ft. in thickness. And this boulder clay, as Mr. Jukes Brown further observes, has forced its way up the sides of the chalk, in places, to a height varying from 300ft. to 400ft.

The Oxford clay, which lies next below the Kimeridge, is a deep sea deposit, dark blue, with brown nodular stones; some of the fossils found in it are Nucula Ornata, Ammonites Plicatilis, A. Rotundus, Cucullæa, Gryphæa Dilatata, Leda Phillipsii, Annelida Tetragona, and A. Tricarinata, Avicula inequivalvis. {94b}

Kellaway’s rock, which lies just below, so called from a village in Wiltshire, near Chippenham, is a mixture of yellowish and buff sands, with brown and buff sandstone. The chief fossils are Gryphæa Dilatata, and G. bilobata, Belemnites in abundance, and Avicula Braam-buriensis. {95a}

The Cornbrash, which succeeds (so called also from a district in Wiltshire, favourable to corn), is a light grey, fine-grained limestone, often so hard as to need blasting. It abounds in fossils. Among them are Avicula Echinata, Ostræa Sowerbyi, Clypeus Ptotii, Ammonites Macrocephalus, A. Herveyi, Nucula Variabilis, Astarte Minima, Trigonia (of four kinds), Modiola (of four kinds), Myacites (five kinds), Cypricardia, Corbicella Bathonica, Pholadomya (two kinds), Cardium (three kinds), Pecten (six kinds), and several more. {95b}

The great Oolite (so named from the Greek Oon, an egg, referring to the number of small stones, like fish-ova, found in it) is divided into Oolite clays and O. limestone. The clays are mottled green and bluish, with bands of ironstone, and concretions of lime. They indicate a shallow sea, as contrasted with the Oxford clay. Fossils are not numerous, but Rhinconella Concinna, Gervillia Crassicosta, Modiola Ungulata, Ostræa Gregaria, O. Sowerbvi, O. Subrugulosa, Perna Quardrata, Trigonia Flecta, and Palate of Fish are found. {95c} These beds correspond to the so-called Forest Marble of the South of England.

The Oolite limestone beds consist of white soft limestones, having at intervals bands of marly clay. This formation burns well, and makes good lime. Its chief fossils are Serpula, Rhynconella, Terebratula, and T. Intermedia, Avicula Echinata, Corbicella, Lima Rigida, Lucina, Modiola Imbricata, Myacites Calceiformis, Mytilus Furcatus, Ostræa Sowerbyi, Pecten Vagans, Pteroperna plana, Trigonia, T. costata, T. flecta, T. striata, T. undulata. {95d}

The Estuarine deposit, underlying the great Oolite limestone, is composed of light blue, green, and purple clays, intersected by soft bands of sandstone, and having at its base a band of nodular ironstone. It is not very fossiliferous, but the following are found:—Rhynconella Concinna, Modiola Imbricata, Ostræa Sowerbyi, Monodonta. {95e} The sandstone bands contain plant-markings in considerable numbers. As its name implies, this formation was produced as the bed of an estuary or tidal river.

The next lower formation is the Lincolnshire limestone. This enters largely into the making of what is called “the Cliff,” which is the high land running south from Lincoln (visible from Woodhall) to the west of the Witham Valley and the Fens. It is a hard building stone, though once the muddy bed of a sea. It is sub-divided into the Hibaldstow and Kirton beds, so called because these strata are exposed in those parishes. Dipping to the east, it underlies the Fens and other upper strata to be found in the Woodhall well. It abounds in fossils, there being as many as 340 species classified, {96a} and consists, indeed, very largely of the hard parts of shells and corals compressed into a solid mass. To a Lincolnshire person, it is sufficient to say of this stone that our grand Cathedral is mainly built of it. We can only give here a few of the more frequent species of fossils:—Three kinds of Echinus, Coral (Thecosmilia gregarea), Serpula socialis, Lima (five kinds), Ostræa flabelloides, Pecten (two kinds), Hinnites abjectus, Astarte elegans, Cardium Buckmani, Ceromya Bajociana, Cyprina Loweana, Homomya Crassiuscula, Isocardia, Cordata, Rhynconella (four kinds); among the bivalves are Avicula Inequivalvis, and A Munsteri, Lima (three kinds), Lucina Bellona, Modiola Gibbosa, Mytilus Imbricatus, Pholadomya (two kinds), Trigonia costata; of univalves, Natica (two kinds), Nerinea Cingenda; of fishes, Strophodus (two kinds). {96b} This is a most useful stone for building purposes. The so-called “Lincoln stone” is largely used in our churches; whilst the “Ancaster quarries,” which also belong to this formation, are famous. The commissioners appointed in 1839 to report on the building stones of England, for the new houses of Parliament, stated that “many buildings constructed of material similar to the Oolite of Ancaster, such as Newark and Grantham churches, have scarcely yielded to the effects of atmospheric influences.” (“Old Lincolnshire,” vol. i., p. 23.) The well-known Colly-Weston slates are the lowest stratum of this rock. The fine old Roman “Newport Arch,” which for some 700 years has “braved the battle and the breeze,” a pretty good test of its durability, is built of this stone.

The base on which this lowest Oolite lies is the Northampton Sands, an irony stratum of red ferruginous sand and sandstone, the upper portion of it also being called the Lower Estuarine deposit. It is from this stratum so many springs arise in various parts of the county, as already mentioned, and among them the Woodhall well water. Its fresh water conditions show it to have been the bed of a great river, but a tidal river, as among the fossils which it contains some are marine shells. In this formation is found the iron-stone, which is worked at Lincoln. Its commoner fossils are Lima duplicata, L. Dustonensis, Hinnites abjectus, Astarte elegans, Cardium Buckmani, Modiola Gibbosa, Ammonites Murchisoniæ, Belemnites Acutus. Its ferruginous layers are (as given by Capt. Macdakin), {97a} Peroxide bed, clay ironstone, hard carbonate of iron, hard blue carbonate peroxidised band, blue ferruginous sand, ironstone nodules, bed of coprolites with iron pyrites.

And this brings us to the Lias formation, in which lies the lower part, amounting to rather more than a third, of the Woodhall wells. It is divided into the upper Lias of clay and shale; the middle Lias of Marlstone rock bed, clay, and ironstone; and the lower Lias of clays, ironstone clays, limestones. {97b} This formation, with a thickness of from 900 to 1,000 feet, runs across England from Yorkshire and Lincolnshire down to the coast of Dorset. The upper Lias of the Woodhall wells also helps to form the slope from 100 feet to 150 feet in thickness of the escarpment called “the Cliff,” to the west of the Witham Fens, and to the north of Lincoln, by Fillingham, and so on. Lincoln itself stands on Lias beds, with a capping of the lower Oolite limestone. {97c} It contains many Belemnites, Lucina, Ammonites Bifrons, A. Serpentinus, A. Communis, A. Heterophillus, Nucula Hammeri, Pleuromyæ, {97d} and especially the Leda Ovum, which distinguishes it from other strata. The middle Lias, which underlies the upper, contains Ammonites Spinatus, A. Margaritatus (in great abundance), Rhinconella, Icthyosauri, Plesiosauri, and fossil wood, etc. {98a} The lower Lias contains Ammonites Capricornus, with many pyrites, A. Ibex, A. Jamesoni, A. Armatus, A. Oxynotus, A. Obtusus, A. Semicostatus, A. Bucklandi, A. Angulatus, A. Planorbis, Gryphœa incurva very abundant, and fossils of many other kinds. {98b} This brings us to the base of the Woodhall Spa wells. For a full list of the fossils so far found at Woodhall, the reader is referred to Appendix II. at the and of this volume.

These strata are shewn in the diagram given at the head of this chapter.

In giving the history of the well in Chapter I., the writer did not state the properties of the Woodhall water; but as these depend upon the geological elements, from which it originates, this seems to be the proper place to state them. The official analysis made by Professor Frankland, F.R.S., 1875, is as follows:—{98c}

Parts Grains per gallon

Total solids in solution 2361.200 1652.8400

Organic carbon .362 .2604

Organic Nitrogen .532 .3724

Ammonia .810 .5070

Nitrogen as Nitrates and .009 .0063 Nitrites

Chlorine 1425.000 997.5000

Total combined nitrogen 1.208 .8456

Bromine 6.280 4.3960

Iodine .880 .6160

Arsenicam .016 .0112

Temporary hardness 20.000 14.0000

Permanent do 245.000 171.5000

Total do. 265.000 185.5000

The water contains unusually large proportions of Iodine and
Bromine.—E. Frankland.

The remarkable features of this analysis are the quantities of iodine and bromine. Professor Frankland, for the Geological Survey, found, of iodine, 6.1 grains in 10 gallons of the water; bromine, 44 grains in ditto.

As compared with the water of Cheltenham, of Leamington, and of the famed German Spa at Kreuznach, we have the original analysis of Mr. West, of Leeds, giving:—

In 10 galls. Iodine. Bromine.

Cheltenham one third grain one and two-thirds grains

Leamington one grain four grains

Kreuznach one and one-quarter grain twenty-five grains

Woodhall six and one-sixth grains forty-four grains

The Woodhall water, therefore, has five times the amount of iodine, and nearly twice the amount of bromine, of the strongest known Continental water. {99a}

I mentioned, in Chapter I., that the Dead Sea, in Palestine, was stronger in bromine than Woodhall. According to M. Marchand’s analysis, it contains bromide of magnesium 74 times the amount at Kreuznach, or about 30 times the strength of Woodhall; but the other great ingredient of the Woodhall water, iodine, is absent from the Dead Sea. {99b} In iodine the only known water surpassing Woodhall Spa is the spring of Challes in Savoy, {99c} which contains 1.045 parts per 100,000 of water.

I may add that at Old Woodhall, about four miles distant from “The Spa,” at a depth of 33 feet, in sinking a well, some 20 years ago, salt water was tapped, resembling in taste that of the Woodhall Spa well, but it gradually became less salt, and finally was replaced by a supply of fresh water. {99d}

There is one other geological feature of the neighbourhood of Woodhall, which has not yet been touched upon, viz., the Fens bordering on the Witham. These are said to have been, to some extent, drained by the Romans; {99e} but within the last few centuries they have been partially reclaimed, have relapsed into bog and morass, and been finally reclaimed for good, in quite recent times. The writer, when a boy, used to visit a large farmer, living in Blankney Fen, whose father built the house in which he resided. Before building, an artificial foundation had to be made, by transporting soil in boats, or carts, from _terra firma_ beyond the Fens, the whole Fen tract being more or less bog and swamp. When this had become sufficiently consolidated, the house and farm buildings were erected upon it; and from that centre roads were constructed, drains made, and the work of reclamation gradually extended. These drains, or “skirths,” as they are sometimes called, were periodically cleaned by a “bab,” a kind of dredge, with hooks at its under side to tear up plant roots. Great flocks of geese were kept, which were plucked alive several times a year, for the sale of the feathers, to make the famed Lincolnshire feather beds, and quills for the pens, now rarely seen, although, 50 years ago, in universal use. Until the land had become systematically reclaimed, it still continued to be extensively flooded in the winter months, and all cattle had to be housed, or penned, during that time, on the artificially raised ground. It frequently happened that early frosts caught the farmer napping, with his cattle still afield; in which case they had to be driven home over the ice, and numbers were at times “screeved,” _i.e._, “split up,” in the process, and had to be slaughtered. The fen soil is a mass of decayed vegetation, chiefly moss, interlarded with silt, deposited by the sea, which formerly made its oozy way as far as Lincoln. Large trees of bog oak and other kinds are found in the soil. These, it is supposed, became rotted at their base by the accumulating peat; and the strong south-west winds, prevailing then as they do now, broke them off, and they are, in consequence, generally found with their heads lying in a north-easterly direction. Borings at different places show the fen soil to vary in depth from 24ft. at Boston to 14½ft. at Martindale; but, as it has been gradually dried by drainage, it has considerably shrunk in thickness, and buried trees, which only a few years ago were beyond the reach of plough or spade, are now not uncommonly caught by the ploughshare.

The river Witham, which the visitor to Woodhall Spa sees skirting the railway, has passed through more than one metamorphosis. Now confined by banks, which have been alternately renewed and broken down at different periods, before the drainage of the Fens, it spread over all that level tract of country, meandering by its many islands and through its oozy channels and meres, the resort of countless flocks of wild fowl and fish _ad infinitum_, but preserving still one main navigable artery, by which vessels of considerable tonnage could slowly sail to Lincoln. Acts were passed, in the reigns of Edward the Third. Richard the Second, Henry the Seventh, Queen Elizabeth, and the two Charleses; and Commissioners were again and again appointed to effect the embanking and draining of these watery wastes, but with only temporary success; and it was not till 1787, or 1788, that the present complete system of drainage was commenced, which is now permanently established. {101a} And in these days, the Fens, once consisting as much of water as of land, at times even suffer from a scarcity of that commodity; drains, which within the writer’s own recollection abounded with fish, being now often dry almost all the year round. At a much more remote period the Witham was probably a much stronger river, and largely conduced to altering the features of the county. This subject has been carefully investigated by our geologists, {101b} with the result that certain changes in the strata of the upper Witham valley, from its source near Grantham, and changes also in the lower valley of the Trent, go far to prove that the Trent, instead of, as it does now, flowing into the Humber, took a more easterly course, and joining forces with the Witham some miles above Lincoln, the united streams pushed their way through the gorge, or “break” in the cliff formation, which occurs there, and is technically known as “The Lincoln Gap,” and continued their course to the sea by something like the present channel of the Witham. The idea of this “Lincoln Gap,” though the term is not actually used, would seem to have originated with Mr. W. Bedford, who stated, in a paper already mentioned, read before “The Lincolnshire Topographical Society,” in 1841, that “the great breach below Lincoln could only be accounted for by the mighty force of agitated waters dashing against the rocks, through long ages”. (Printed by W. and B. Brookes, Lincoln, 1843, p. 24, &c.) The theory would seem to be now generally accepted. Thus: “that ancient river, the river” Witham, honoured, we believe, by the Druid as his sacred stream, {102} consecrated in a later age to the Christian, by the number of religious houses erected on its shores, through a yet earlier stage of its existence performed the laborious task of carving out the vale of Grantham, and so adding to the varied beauty of our county; then, by a kind of metempsychosis of the river spirit, it was absorbed in the body of the larger Trent; the two, like “John Anderson, my Joe,” and his contented spouse, “climbed the hill together,” to the Lincoln Gap, and hand in hand wended their seaward way, to help each other, perchance, in giving birth to the Fenland; or, according to another theory, in making its bed. Through a long era this union lasted; but, as the old saying is, “the course of true love never did run smooth”; a change geologic came over the scene, and, through force of circumstance, the two, so long wedded together, broke the connubial bond, and henceforth separated, pursuing each their different ways; the one, the Trent, the river of thirty fountains, betaking herself “to fresh woods and pastures new,” after brief dalliance with the Ouse, became bosomed in the ample embrace of the Humber; the other, the humbler stream of the two, retaining its previous course, pursued the even tenor of its way through the flats of the Fenland, with their “crass air and rotten harrs,” to find its consolation in the “dimpling smiles,” but restless bosom, of the shallow “Boston Deeps.” During the period of that ancient alliance of these two streams the tract of country between Lincoln and Boston, or rather between the points now occupied by those places, would be scoured by a greatly-augmented volume of water, and this may possibly account in some degree for the shallowness of “The Wash,” and the number of submarine sandbanks which lie off the mouth of the present Witham. Had the union of the two streams continued to the present time, bringing down their united body of silt, Boston would either never have come into existence at all, or would have been much further from the sea than it is.

The precise period at which this riverine union prevailed would seem to be still an open question; and we may say, with Horace, _adhuc sub judice lis est_; for, whereas Professor Archibald Geikie, Director-General of the Government Geological Survey, {103a} gives his opinion that “the gravels which have been laid down by an older Trent, that flowed through the gorge in the Jurassie escarpment at Lincoln, were later than the glacial deposits”; on the other hand, Mr. F. M. Burton, F.L.S., F.G.S., {103b} who has a thorough local knowledge of the county and its geological features, says there is sufficient evidence “to convince any reasonable mind that the present course of the Trent is not its original one; but that ages ago, in early pre-glacial times, I think, it passed through the Lincoln Gap to the fenland beyond, which was then open bay.” We may well say with Pope: “Who shall decide when doctors disagree?” {103c} This, however, is too large a subject for a chapter on the geology of Woodhall Spa; but this brief reference to it may serve to show the visitor, who has the taste and inclination for such pursuits, that there are still subjects for interesting investigation in our neighbourhood, on which he might well employ his capacities for research.