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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Nov, 



companies proposeJ some years ago to establish swift boats that misht 

 compete with the mail coaches. (Jn beini; applied to by them, his lirst 

 attempt was to build one with a spheroidal bow, produced by the revolu- 

 tion of an ellipse ; but the result was not as successful as was to be 

 ■wished. The favourite shape of bow among seamen at the time was that 

 called a duck's breast, but the ell'ect was to raise a large wave immedi- 

 ately in frout of the vessel, which of course considerably retarded its 

 velocity. He then directed his attention to the motion of the water itself. 

 When a vessel passed through the water at a great velocity a high wave 

 was raised at the head, as high in the old steamers as four feet; and this 

 wave on falling back formed a hollow by its pressure immediately behmd 

 it, and the water was afterwards sent out with great force on both sides of 

 tiie bow. All this was a costly and useless expenditure of force. He 

 thought that, in removing the particles of water to allow the vessel to 

 pass, it was necessary to expend the least force on the whole; and, there- 

 fore, the tirst impulse should be given gently. This force should increase 

 to a certain poiut, and then decrease as gradually, leaving the particles to 

 rest quietly at the greatest breadth. la endeavouring to ascertain the 

 least resistance necessary to bring the particles of water out of a state of 

 rest he conceived that there ought to be a similarity between the motion of 

 water and that of a pendulum revolving in a circle according to the curve 

 of the vessel's size; and this led him to adopt the form known as the wave 

 principle. This is different from a bow formed of two straight lines meet- 

 ing at an acute angle, in being gently hollower than such a bow towards 

 the cut-water, and a little rounder towards the greater breadth. The object 

 to be attained was, he conceived, to remove the particles of water rapidly, 

 and al tlie same time not to throw them farther aside than the breadth of 

 the vessel amidships. That this object was effected by the wave principle 

 he ascertained in the following manner : — He got his model boat, 75 feet 

 long, to be carried along by high-bred horses at a speed of 17 miles an 

 hour, and made the head pass between two oranges floating on the water, 

 and which be intended to represent two particles of the water to be re- 

 moved. The oranges merely touched the side of the vessel until they got 

 amidships and there remained ; thus showing that no greater force had 

 been appliid to them than was necessary to remove them out of the way 

 of the \essel. Another phenomenon observed was, that, instead of the 

 high wave at the bow, which sailors thought was a sign of a ship sailing 

 well, or VI hat they called carrying a bone in her teeth, the elevation and 

 subsequt-nt depressson of the water were entirely got rid of. In their 

 place there was a gentle, long elevation, just under the shoulder of the 

 vessel, where all sailors would like her to be supported. For the closing 

 of the water at the stern he at first thought it would be better to have the 

 same shape behind ; and this had the efl'ect of bringing the oranges 

 together again behind in an horizontal direction ; but he found it did not 

 answer at all. It occasioned too high a resistance, and had a multitude 

 of bad qualities. He discovered, in fact, that the fuller she was behind, 

 and the flatter she lay upon the surface of the water, the quicker she 

 sailed : and that this should be the case is clear, when it is considered 

 that the water, returning to its level, is governed by an entirely different 

 law from that by which it is first separated. The power which sends the 

 water into the wake has nothing to do with that which displaces it before. 

 It is forced upwards by the greatest pressure from below in vertical lines 

 of the cjcloidal family. A run fine below and full above was attained by 

 many experiments, as the best for good steering and other qualities. This 

 full water-line above should never exceed a cycloid. The vertical lines, 

 in which the water rises in the secondary wave (which really replaces 

 the displaced water) may he cut oil', at any convenient height, close to the 

 stern. These two considerations united led him to the adoption of what is 

 known as the wave principle. In the wave formation the greatest breadth 

 of the ship is not at the bows, or even amidships, but a great way aft, in 

 the ratio of three to two. In the shear plan the bow of this form has one 

 main cycloid, and all the other bow lines are parts of cycloids. In this 

 form the particles ascend and descend without shock. 



Mr. ViGNOLLEs asked if the Admiralty had got vessels built on this 

 principle, — and if nut, u-liy luitf 



Mr. Scott Russell replied, that he had been much more desirous for 

 the adoption of the system in other ships than in the Admiralty, because 

 he had been informed that the Admiralty did not like tiie introduction of 

 scientific principles into ship-building, and preferred remaining as they 

 were. He had, therefore, been averse to obtrude the subject on ihera. 

 He might state, however, that the best informed men at the Admiralty 

 were aware of the existence of the wave principle ; and it was not impro- 

 bable they might adopt it, although he could not say how soon, nor to what 

 extent. 



Professok Owen's Geological Lecture. 

 Extinct Animals of Great Britain. 

 In one of the evening lectures the Professor commenced by stating 

 that he proposed to submit to the learned and distinguished assembly 

 which he had the honour of addressing some of the general conclusions 

 which he had deduced from a study of the fossil remains of the class mam- 

 malia discovered in the soil of Great Britain ; and he deemed it fortunate 

 to have tliis opportunity of showing what enlarged and unexpected views 

 of ancient nature might be obtained from dry comparisons and descriptions 

 of processes of hone and tubercles of teeth, and he hoped to make those 

 views iutelligible to all, without the obscuratioa of technical auatomical 

 terms. He proposed, first, briefly to notice the principal forms or kinds of 



mammalian quadrupeds that had been successively introduced into the 

 portion of earth which now constituted our island ; secondly, to consider 

 the mode of their introduction here, and their relations to existing species 

 at present localised in Europe and Asia ; and, finally, to point out the cor- 

 respoudence between the existing and extinct groups of mammalia pecu- 

 liar to other great natural divisions of dry land. 



Animals Preceding the Oolitic Period. 

 We discern, he said, the earliest trace of the warm-blooded, air-breathing 

 viviparous quadrupeds at that remote period which immediately preceded' 

 the deposition of the oolitic group of limestones. The massive evidence 

 of the operation of the old ocean, from which those rocks were gradually 

 precipitated, extends across England, from Yorkshire on the north-east to 

 Dorsetshire on the south-west, with an average breadth of nearly thirty 

 miles ; and from some land which formed die southern shore of this arm 

 of sea, were washed down the remains of small insectivorous, and proba- 

 bly marsupial quadrupeds, distinct in genus and species from any now 

 known in the world. With these small mammals there occur elytra of 

 beetles, and debris of cycadea; and other terrestrial plants. The character 

 of some of these vegetable fossils and of the associated shells, as the tri- 

 gonia;, and the great abundance, in the oolitic ocean, of fishes whose near- 

 est living analogue is the cestracion, recall many of the characteristic fea- 

 tures of actual organic life in Australia. From the remote period in which 

 the remains of mammals first make their appearance to that in which we 

 again get indubitable evidence of their existence, a lapse of time incalcu- 

 lably vast has occurred. We trace it, though inadequately, by the succes- 

 sive deposition from seas and estuaries of enormous masses of rocks of 

 various kinds, the graveyards of as various extinct forms of animal and 

 vegetable life. The shelly limestone slate, which contains the bones of the 

 amphitheria and phascolotheria, lies at the base of the inferior oolite 

 Upon it have been accumulated the enormous masses of the great oolite' 

 the cornbrash, and the forest marble ; and upon these have been success- 

 ively piled the Oxford clay and coral rag, the Kimmeridge clay and Port- 

 land stone. In the still more enormous masses of Wealden rocks, rising 

 to the height of eight hundred feet, and deposited after the formation of 

 the Portiand sands by the water of an immense estuary, no true indica- 

 tions of warm-blooded animals have been hitherto discovered. Four hun- 

 dred feet deep of gault and greensand rest upon the Wealden, but reveal 

 no trace of cetacean or other form of mammalian life. Over these founda- 

 tions of the present south-eastern part of our island the ocean continued 

 to roll, but under influences of heat and light favourable to the develop- 

 ment of corals and microscopic calcareous shells, during a period of tinie 

 which has permitted the successive accumulation of layers of these skele- 

 tons, in a more or less decomposed state, with probable additions from 

 submarine calcareous and siliceous springs, to the height of one thousand 

 feet. But although amongst the remains of higher organised animals that 

 have become enveloped in the cretaceous deposits there have been recog- 

 nised birds, pterodactjles, and a land-lizard, probably washed down from 

 some neighbouring shore, no trace of a mammalian quadruped has yet 

 been discovered iu them. The surface of the chalk, after it had become 

 consolidated was long exposed to the eroding action of waves and currents 

 Into deep indentations so formed have been rolled fragments of chalk and' 

 flint, with much sand. The perforations of marine animals on that surface 

 have been filled with fine sand ; and there are many other proofs of the 

 lapse of a long interval of time between the completion of the chalk de- 

 posits of Britain and the commencement of the next or tertiary era. Of 

 this era our present island gives the first indication in traces of mighty 

 rivers, which defiled the fair surface of the rising chalk by pouring over 

 it the debris of the great continent which they drained,— a continent which 

 has again sunk, and probably now lies beneath the Atlantic. The masses 

 of clay and sand that have been thus deposited upon the chalk are accu- 

 mulated chiefly in two tracts, called the London and Hampshire basins 

 which seem to have been two estuaries or mouths of the great river ■ tlie 

 one extends from Cambridgeshire through Hertfordshire and Suffolk to 

 the North Downs, the other from the South Downs into Dorsetshire. 



At the time when these vast but gradual operations were takino- place 

 an arm of sea extended from the north to the area called the basin of Paris' 

 which received the overflow of a chain of lakes extending thither from' 

 the highest part of the central mountain group of France. An enormous 

 mass of mixed or alternaUng marine and fresh-water deposits was accumu- 

 lated in this basin, coeval, if we may judge from the identity of the spe- 

 cies of shells, with the outpouring of eocene, London, and plastic clavs 

 upon the English chalk. ^ 



Eocene Animals. 



The proofs of the abundant mammalian inhabitants of the eocene conti- 

 nent were first obtained by Cuvier from the fossilised remains in the de- 

 posits that fill the enormous excavation in the chalk called the Paris basin 

 But the forms which that great anatomist restored were all new and 

 strange; specifically, and for the most part geneirically, distinct from all 

 known existing quadrupeds. Long before any discovery had been made 

 of remains of terrestrial mammals in the contemporary Lo'ndon and plastic 

 clays, the existence of neighbouring dry land had been inferred from the 

 occurrence in those deposits of bones of crocodiles and turtles, and from 

 the immense number of fossil seeds and fruits, resembling those' of tropical 

 trees, as pandani, cocoa-nuts, &c. 



Scanty as are the eocene mammalia hitherto discovered in the London 

 clay, they are highly interesting from their identity or close affinity with 



