and the greater size of the mouth. The absence of a lip makes it less effective for burrowing and sessile creatures, but the weighted ground rope nevertheless secures them to a very surprising extent. The position of the ground rope is an important feature, as any free swimming creature not disturbed until the arrival of the ground rope cannot escape by simply rising or “striking” up. This and the greater spread make the trawl especially suitable for the collection of fishes and other swiftly moving animals. The first haul of the “Challenger” trawl brought up fishes, and most of our knowledge of fish of the greatest depths is due to it.
 |
| From Alexander E. Agassiz’s Three Cruises of the “Blake.” By permission of Houghton, Mifflin & Co. |
| Fig. 18.—Agassiz or Blake Trawl. |
A tendency to return to the use of the small beam trawl for deep-sea work has lately shown itself. That used by Tanner on the “Albatross” has runners more heart-shaped than the “Challenger’s” instrument; the net is fastened to the downward and backward sloping edge of the runner as well as to the beam, being thus fixed on three sides instead of one; and a Norwegian glass float is fastened in a network cover to that part of the net which is above and in front of the ground rope in use, to assist in keeping the opening clear. These floats can stand the pressure at great depths, and do not become waterlogged as do cork floats. The largest “Albatross” trawl has a beam 11 ft. long, runners 2 ft. 5 in. high, and its frame weighs 275 ℔.
Agassiz or Blake Trawl.—This is generally considered to possess advantages over the preceding, and is decidedly better for those not experts in trawling. Its frame (fig. 18) consists of two iron runners each the shape of a capital letter D, joined by iron rods or pipes which connect the middle of each stroke with the corresponding point on the other letter. The net is a tapering one, its mouth being a strong rope bound with finer rope for protection till the whole reaches a thickness of some 2 in. It is fastened to the frame at four points only, the ends of the curved rods, and thus has a rectangular opening.
The chief advantage of this frame is that it does not matter in the least which side lands first on the bottom; it is to the other trawls what Ball’s dredge is to an oyster dredge. The course can also be altered during shooting or towing the Blake trawl with far greater ease than is the case with others. An Agassiz trawl very successful in the North Sea has the following dimensions: length of the connecting rods and therefore of the mouth 8 ft., height of runners and of mouth 1 ft. 9 in., extreme length of runners 2 ft., length of net 11 ft. 3 in., weight of whole trawl 94 ℔, 63 of which are due to the frame.
It is instructive to note how closely our knowledge of bottom-living forms has been associated with the instruments of capture in use. As long as small vessels were used in dredging, the belief that life was limited to the regions accessible to them was widely spread. The first known denizens of great depths were the foraminifera and few echinoderms brought up by various sounding apparatus. Next with the dredge and tangles the number of groups obtained was much greater. As soon as trawls were adopted fish began to make their appearance. The greatest gaps in our knowledge still probably occur in the large and swiftly moving forms, such as fish and cephalopods. As we can hardly hope to move apparatus swiftly over the bottom in great depths, the way in which improvement is possible probably is that of increasing the spread of the nets; and a start in this direction appears to have been made by Dr Petersen, who has devised a modified otter sieve which catches fish at all events very well, and has been operated already at considerable depths.
Of the economy of quite shallow seas, however, we are still largely ignorant. Much as has been learnt of the bionomics of the sea, it is but a commencement; and this is of course especially true of deep seas. The dredge and its kindred have, however, in less than a century enabled naturalists to compile an immense mass of knowledge of the structure, development, affinities and distribution of the animals of the sea-bed, and in the most accessible seas to produce enumerations and morphological accounts of them of some approach to completeness. (J. O. B.)
DRELINCOURT, CHARLES (1595–1669), French Protestant divine, was born at Sedan on the 10th of July 1595. In 1618 he undertook the charge of the French Protestant church at Langres, but failed to receive the necessary royal sanction, and early in 1620 he removed to Paris, where he was nominated minister of the Reformed Church at Charenton. He was the author of a large number of works in devotional and polemical theology, several of which had great influence. His Catechism (Catéchisme ou instruction familière, 1652) and his Christian’s Defense against the Fears of Death (Consolations de l’âme fidèle contre les frayeurs de la mort, 1651) became well known in England by means of translations, which were very frequently reprinted. It has been said that Daniel Defoe wrote his fiction of Mrs Veal (A True Relation of the Apparition of Mrs Veal), who came from the other world to recommend the perusal of Drelincourt on Death, for the express purpose of promoting the sale of an English translation of the Consolations; Defoe’s contribution is added to the fourth edition of the translation (1706). Another popular work of his was Les Visites charitables pour toutes sortes de personnes affligées (1669). Drelincourt’s controversial works were numerous. Directed entirely against Roman Catholicism, they did much to strengthen and consolidate the Protestant party in France. He died on the 3rd of November 1669.
Several of his sons were distinguished as theologians or physicians. Laurent (1626–1681) became a pastor, and was the author of Sonnets chrétiens sur divers sujets (1677); Charles (1633–1697) was professor of physic at the university of Leiden, and physician to the prince of Orange; Peter (1644–1722) was ordained a priest in the Church of England, and became dean of Armagh.
DRENTE, a province of Holland, bounded N. and N.E. by Groningen, S.E. by the Prussian province of Hanover, S. and S.W. by Overysel, and N.W. by Friesland; area, 1128 sq. m.; pop. (1900) 149,551. The province of Drente is a sandy plateau forming the kernel of the surrounding provinces. The soil consists almost entirely of sand and gravel, and is covered with bleak moorland, patches of wood, and fen. This is only varied by the strip of fertile clay and grass-land which is found along the banks of the rivers, and by the areas of high fen in the south-eastern corner and on the western borders near Assen. The surface of the province is a gentle slope from the south-west towards the north-east, where it terminates in the long ridge of hills known as the Hondsrug (Dog’s Back) extending along the eastern border into Groningen. The watershed of the province runs from east to west across the middle of the province, along the line of the Orange canal. The southern streams are all collected at two points on the southern borders, namely, at Meppel and Koevorden, whence they communicate with the Zwarte Water and the Vecht respectively by means of the Meppeler Diep and the Koevorden canal. The Steenwyker Aa, however, enters the Zuider Zee independently. The northern rivers all flow into Groningen. The piles of granite rocks somewhat in the shape of cromlechs which are found scattered about this province, and especially along the western edge of the Hondsrug, have long been named Hunebedden, from a popular superstition that they were “Huns’ beds.” Possibly the word originally meant “beds of the dead,” or tombs.
Two industries have for centuries been associated with the barren heaths and sodden fens so usually found together on the sand-grounds, namely, the cultivation of buckwheat and peat-digging. The work is conducted on a regular system of fen colonization, the first operation being directed towards the drainage of the country. This is effected by means of drainage canals cut at regular intervals and connected by means of cross ditches. These draining ditches all have their issue in a main drainage canal, along which the transport of the peat and peat-litter takes place and the houses of the colonists are built. The heathlands when sufficiently drained are prepared for cultivation by being cut into sods and burnt. This system appears to have been practised already at the end of the 17th century. After eight years, however, the soil becomes exhausted, and twenty to thirty years are required for its refertilization. The cultivation of buckwheat on these grounds has decreased, and large areas which were formerly thus treated now lie waste. Potatoes, rye, oats, beans and peas are also largely cultivated. In connexion with the cultivation of potatoes, factories are established for making spirits, treacle, potato-meal, and straw-paper.
