388 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[November, 



also to the principal engineers and scientific institutions of the metropolis ; 

 and we recommend the same accordingly. 



All which we submit to the judgment of this hon. court. 

 Dated this 15th day of September, 1841. 



j. w. a.nderton. 

 John" Raxs. 

 George Selson. 



E. EVTON. 



Charles noNn. 

 William Mcddell. 

 James Uooi.e. 



J. Ml'SGROVE. 



JoHV Adamson. 

 W. Simpson. 

 George M'Kenzie. 

 James Davies. 

 W. A. BECKWaTH. 



The report was then ordered to be printed aud circulated, and taken into 

 consideration on a future day. 

 After the transaction of some further business, the Court adjourned. 



ENCROACHMENT OF THE SEA AT DOVER. 



Tuesday Evening, 19/A October. 

 DcRiNG the last three or foiir days the very boisterous weather which all 

 along the south-eastern coast has more or less been detrimental to the ship- 

 ping interest, has done considerable damage at Dover, carrying away an im- 

 mense quantity of beach, and undermining a number of boat-houses and 

 other small buildings which had for a number of years past bid defiance to 

 the fury of the waves. In the bay, which to a considerable extent was 

 sheltered from the wind and tide by the projection of the pier, several boat- 

 houses opposite the Royal York Hotel have been washed down. For several 

 days past, during the time of high water, the waves have come rolling into 

 the bay in such awfid grandeur as is rarely witnessed on this coast, carrying 

 back with them the shingle to so great an extent that the sea now washes in 

 10 or 15 feet nearer the ilarine-parade and Waterloo-crescent than it for- 

 merly did. The greatest destruction of property, however, has been to the 

 westward of the Stonebead. Here, where the beach used formerly to accu- 

 mulate in great quantities, and passing hence to the month of the harbour, 

 whereby a free ingress and egress to vessels was prevented scarcely a pebble 

 is to be seen — a phenomenon never before witnessed by the oldest in- 

 habitant. 



What can be the cause of this extraordinary circumstance, is difficult, per- 

 haps, to determine, although the most probable conjecture is, that the enor- 

 mous fall of chalk at the Round Down Clifl', about twelve months since, has 

 stopped the progress of the shingle beyond it, in travelling to the eastward, as 

 it used to do. But some persons, who have paid considerable attention to 

 the subject, conclude that it arises from the large quantity of beach used in 

 the construction of the sea-wall between this town and Folkestone. The 

 circumstance, however, from whatever cause it may arise, is a subject for 

 deep regret, as the presence of the beach was a great preservative to the 

 town, while its absence has been the sole cause of the late destruction of 

 property. 



We have not been able to ascertain the amount of the damage sustained 

 in this part of the town, but as the buildings belonged principally to boat- 

 men and the humbler classes of society, they are of a serious nature ; whilst 

 future gales threaten more extensive destruction, unless something be done 

 to check the raging waves. Further onward is the Bullock rock, on which is 

 built ArchcIitT Fort, the residence of Colonel Munro, R. A., the commandant 

 of the garrison. The base of this rock we perceive has also been undermined 

 to a very great extent by the washing of the sea, and as there are several large 

 clefts in various parts of it, there is every reason to fear that a portion of it 

 will soon give way. The houses beyond this rock have been by the late 

 gales placed in imminent danger. The platform on which they were built, 

 and which extended several feet in front, has nearly all been carried into the 

 sea, and some of the smaller buildings, one of which was the residence of a 

 poor family, have been pulled down to prevent the materials being washed 

 into the sea, and to make a road to the other houses. The platform leading 

 to the entrance of the tunnel under Shakapcare Cliff, which was many feet 

 in width, has also disappeared, with the exception of a narrow slip ; but as a 

 second tunnel is yet to be excavated, we do not apprehend that it will be of 

 any loss to the South Eastern Railway Company. One thing, however, is 

 now quite certain — the company will not be able to make the railroad in 

 this place stand, without going to the c pense of erecting a wall to defend it 

 from the encroachment of the sea ; and this, it appears to us, w ould be ad- 

 visable before the Dover terminus of the tunnel be commenced, if the mate- 

 rials for the construction of the same can be obtained. The whole of the 

 beach, as wc before obsened, having been carried away, nothing now remains 

 to prevent the sea washing against that vast and stupendous cliflF which 

 Shakspeare has immortalized, and we perceive tliat even here also the raging 

 jurf seems fully bent upon destruction. A large quantity of several thou- 

 and tons' weight fell into the sea on Sunday last, near the mouth of the 



railway tunnel, and many other huge masses may be seen at a distance tot- 

 tering over an excavated base. A walk, therefore, beneath this cliff may now 

 be considered as extremely dangerous. 



The attention of many of the inhabitants of Dover is now turned towards 

 the object of preventing the sea making any further encroachments on the 

 town, and for this purpose a deputation of them yesterday morning waited 

 on Mr. Jcnkinson, the Deputy Lieutenant Governor of Dover Castle, to as- 

 certain if any assistance could be rendered by the Harbour Commissioners. 

 The deputation was received by .Mr. Jenkinson with every mark of respect, 

 and he informed them that everything that he, as a Harbour Commissioner, 

 could do should be done, and that he would immediately communicate with 

 His Grace the Duke of WelUngton on the subject. 



A .STEAM BOAT OF A NEW CONSTRUCTION. 

 (Abridged from the New York Herald, August 7.) 



The new steam boat, the Germ, is arrived in our waters, and has made an 

 experimeutal trip off the Battery. Lieutenant Hunter, the inventor of this 

 boat, and Captain Hosken, of the Great Western, took a trip in her yesterdr.y, 

 through our harbour and round the Nor'.h Carolina, and were highly gratified 

 with her performance. This beautiful little vessel is just 50 feet in extreme 

 length : width of beam at the water line 9 feet, at the gunwale 1 1 feet. The 

 area of her displacement at the greatest breadth of beam is a fraction over 

 20 square feet. .She is propelled easily 8 miles an hour ; and, with better en- 

 gines, could easily be propelled 1 1 miles an hour. She has two engines ; each 

 of which, if properly constructed, would be equal to uhat is called five horse 

 power; they are, however, so indifferently arranged, as to work at a loss of 

 one-third of «hat should be their power ; and have therefore together but six 

 and two-thirds horse power. Calculating on this data, it will be seen that 

 the propulsive power used in the " Germ" is equal to one horse for every 3 

 square feet ; whereas the propulsive power used for our fastest steamers it 

 equal to three burses for every square foot of displacement. The contrast, 

 therefore, is very great. The well established fact, that the power necessary 

 to prone! a vessel is estimated by the area of her displacement at the greatest 

 breadth of beam, and the advantage of speed known to resu't from great 

 length of keel, and the application of paddle wheels of greater diameter, 

 leaves us the interesting and valuable truth clearly self-evident, that the 

 submerged horizontal paddle-wheels (like that in the Germ) is a much more 

 eflicient propeller than the paddle-wheel now in use. The great advantages 

 consequent on the use of this new kind of propeller, for ocean navigation, is 

 too evident, therefore, to require much stress. By its lateral action, the 

 movement of the vessel is always under control ; she is in no danger from 

 broaching to, or bringing by the lee ; as by the peculiar power of her paddles 

 in the lateral action, she can easily be brought out of the truuj^h of a sea, 

 and be made to " head it," without the aid of a rudder, or without headway 

 on her. And, more than this, the propellers being at all times submergeti, 

 the vessel moves through head sea with but little diminution of her speed. 

 The Germ has the appearance of a handsome canal boat. No « heels arc 

 seen, very little smoke, and a very small escape pipe, are all that tell she is 

 a steam boat. She moves with great velocity, and perfectly noiseless, with 

 scarcely any rippling of the water. She turns easily, almost upon her own 

 centre. Half ilie boat is formed into a neat cabin; the forward half is occu- 



Eied by the engine and boiler, which is on the high-pressure plan. The 

 oiler is made on the locomotive plan (.ind it appears to have been a locomo- 

 tive boiler, at some time), with cylinders attaclied to it, larboard and star- 

 board. In the cy inder works a small piston rod 18 inches long, from this 

 e.\lends the connecting-rod, about four feet lung ; and this last rod is attached 

 directly to the paddle-wheel crank. The crank on each side is connected 

 with a vertical shaft that works the paddle-wheels exactly like a man work- 

 ing two coili-e mills with his tuo hands. The great feature in this boat, that 

 is the propeller, consists of a hollow iron hub. four feet diameter, with pad- 

 dles made of boiler iron radiating from it. The superficies of each paddle is 

 one-half of a square foot, therefore the whole ditmetcr of the paddle wheel Is 

 exactly five feet. There are two of these paddle wheels, the space betweea 

 them being occupied by the keelson. These paddle wheels camiot be injured 

 by the vessel's f;roundinjj. for the bottom of the vessel (which can be made 

 of any desired thickness) is always below the paddle wheels, ground where 

 she may. The Germ has an advantage over all vessels otherwise propelled, 

 in not requiring a rudder to direct her course, by reason of the lateral aclioa 

 of her wheels. She has a rudder, but it is more for convenience than actual 

 use. It w ill be easily seen, too, that the hull of a steamer thus constructed 

 must be subject to less wear and tear than all others, for the power of the 

 engine is imparti-d in a line with the keel, and at a point most available for 

 propelling. Again, the paddle wheils are not subject to the irregular action 

 of the sea, and therefore they have always a uniform resisting power, and her 

 engines work smoothly. 



On the other hand, if a vessel thus constructed chose to u.';e sails, her pad-_ 

 die wheels offer less resistance than those of any other steam boat ; take oft" 

 the connecting rods and her wheels do not present a resistance of half a knot 

 out of every ten knots. Her paddle wheels are of iron, made very simple but 

 strong. They are not liable to get out of order ; and although made of boiler 

 iron, are so buoyant as to float, owing to the displacement caused by the 

 hollow hub in the centre. Such is the Germ, and such is the new and im- 

 portant principle in the propulsion of vessels which has been conclusively 

 established by the performance of this little vessel. 



The fitness of these propellers to canal navigation has been fully settled 

 by the actual working of the Germ on several canals, and the privileges 

 already given to Lieutenant Hunter, by the directors, for the use of ni» 

 valuable improvement. 



