I 21 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[April, 



Fig. 2. — View uf Whit.suiiilay I>luiul. 



_iLt. 



Fig. 3. — Section of Whitsunday Island. 



The channel leadhig from the sea into the lagoon is nearly always 

 a deep narrow passage, which is kept open by the etHiix of the sea 

 at low tides. Lyell observes, that it is sufficient that a reef should 

 rise a few feet above low water mark to cause the waters to collect 

 in the lagoon at high tide, and when the sea falls, to rush out 

 violently at one or more points. This, he remarks, is strictly 

 analogous to that witnessed in our estuaries, (where a body of salt 

 water accumulated during the flow,) issues with great velocity at 

 the ebb of the tide, and scours out or keeps open a deep passage. 



We see from these extended examples that Mr. Tait's principle 

 is one that is neither unsanctioned by example nor useless iu its re- 

 sults, although in the present state of science we have not perhaps 

 the opportunity of carrying it out artificially upon the great scale 

 which is exhibited to us by nature. The force of volcanic action, 

 which can elevate reefs from the depth of the ocean, our greatest 

 steam power cannot imitate ; but the day may perhaps come when 

 we may be able to employ this agent with the same ease that we do 

 the strength of the ocean. 



CURTIS'S RAILWAY IMPROVEMENTS. 



We have before had tlie pleasure of recording several of Mr. Curtis's 

 railway improvements, and we now add two otliers, well deserving the 

 serious attentimi of all railway companies, for arresting those awful 

 accidents, " collisions of trains," which, we are sorry to say, we see too 

 often recorded in the daily papers to the injury of railways. We con- 

 sidcr hotli contrivances admirably well adapted for the purposes 

 intended by the ingenious inventor; they form part of several other 

 improvements for wliicli Mr. Curtis has recently received her Majesty's 

 letters patent. In our ne.Kt number we shall give some particulars of 

 his other inventions. The following descriptions we extract from tlie 

 specitiration of tlie patentee : — 



A Break or Carriage for arrestinf) the Progress of an Enyine or 

 Carriage,, and which in mi nho be applied for clenrinc/ the Line of impedi- 

 ments placed or li/iiiq iiponit. — Tlie best form of this brake is shown in 

 tig. 1, 2. an! 3; tig. 1 is a side view, and tig. 2 an end view of the same, 

 it may be placed either in front as shown, or behind the engine or car- 

 riage ; hui I prefer the front of the engine, because it is made then to 

 act as a means of clearing the line as above stated. 



A shaft. V '\> placed across the framing of the engine, and upon this 

 shaftare Hxed llu- two legs or levers, C C, and to tlie lower ends of the 

 levers are attaclied the snoes, E. E., by the pins of the connecting rod, 

 G., but in cases where the connecting rod, G., would not clear the 

 timlienrig of the hriilges of the line it may be omitted and the joints 

 made hy pins (.mly ; the cross-bars may be either omitted or placed 

 higher on the parallel rods, D D, used to keep the lower surfaces 

 of ihe shoes parallel with the rails, and to give them a certain degree 

 of steadiness; ti:e shoe is formed either of wrought or cast iron, or of 

 timber shod wiili iron, with a flange upon its inner edge to correspond 

 with tlie flatiL'cs of the wheels ; the back end is formed to the curve of 

 the contiu'""ns wheel, so that where it is in gear it impinges against it, 

 and ilie Han e of the wheel enters the grooves formed in the shoe, and 

 thus very n aterially adds to the stability of theapparatus. The groove 

 is shown cl.arly in figure 3, which shows the upper plan of the 

 shoe, and lig. i tlie under side of the same. A rubbing piece of wrought 

 iron or other metal may be introduced into the under side of the shoe, 



and secured by rivets or other means, which can be renewed as it 

 becomes worn out by the friction of the rails when in contact with them. 

 A crank is fastened upon one end of the cross-shaft, K, to which iscon- 

 nected the rod, B; the other end of this rod is connected with the lever 

 A, working upon a pivot, by wliitli the engineer can work the brake as 

 circumstances may require ; the cross-shaft is connected by the carriage 

 to the frame in the usual way, and the pin makes likewise the connexion 

 of the parallel rod, D, at its upper end, and the pin at its lower end ; 

 the lever may be substituted by a screw, whicli may be made to act in 

 a line with the connecting rod, B, for the purpose of working the 

 apparatus, oranyotlierfit and suitable leverage may be adopted. When 

 the engineer observes anything upon the line he is desirous to remove 

 with the brake, he depresses the shoes to within a very short distance of 

 the rail, whicli distance may be denoted by a stop placed upon anarched 

 segment, against which the lever. A, may work, or by any of the usual 

 means for the same purpose, and when he is desirous to stop the engine 

 he causes the brake to come into contact with the rails by moving ths 

 lever. A, further forwards, and if to stop the engine as short as possible, 

 the lever is thrown forward until it occupies the place shown by the 

 doited lines, when the apparatus assumes the position also shown by the 

 dotted lines in figure l,the efl'ect of which is to raise the engine a 

 space equal to that included between the black and dotted lines. 



The force required on the part of the engineer to produce this eflTect 

 is very trifling, because the momentum of the engine forces the shoe 

 into g( ar as soon as it is brought firmly into contact with the rails ; the 

 springs, by their re-action, still keep the wheels upon the rails, but the 

 weight being transferred for the most part to the brake, the tractive 

 power of the driving wheels is very much reduced, at the same time 

 such an extensive rubbing surface is brought into action that it will be 

 sufficient to bring the engine to a dead stop although the steam may not 

 be shut ofl^. It is evident by examining the figures that aiiv degree of 

 retardation may be produced between that necessary to bring up the 

 engine and that slightly to check its velocity, as in descending inclined 

 planes and by moving the lever more or less forward, and the leverage 

 must be also sufficiently powerfiil of whatever kind it may be formed, 

 so that the shoes may be drawn out of gear without stopping the 

 engine. 



An Apparatus to prevent Collisions between Trains on the same Line 

 of Kails. — This apparatus is shown in figures 5 and 6. Figure !'> is a 

 bide view of the apparatus and an engine in contact with it, attached 

 to the last carriage of a train, and figure 6 is a plan of the same. 



The sledge or retarder, A, is formed like a wedge, with its superior 

 end turned up upon the inner side ; flanges are formed, so as keep it 

 upon the rails, the two sides are united together by the cross-bar, J, 

 the plate, K, and the cross pieces, G G, and the sides are set to tha 

 same gauge as the rails, so that an engine may run upon it without 

 difficulty to the cross-bar, J ; two buffers, D D, are fixed, which 

 correspond with other buffers, I, formed upon the fr-nt frame of tho 

 engine, so that when the engine comes in contact with the retarder 

 these buffers receive the concussion ; the plale K is used, in order to 

 unite the sledge as near to the point as possible, and still to allow a 

 free passage to the flanges of the wlieels ; to the cros* pieces G G, tha 

 spring ]i!eces, B B, are fixed, which form shifts for the wheels C, 

 upon which the apparatus is carried when out nf gear ; E is a counter- 

 balance weight to counterpoise the weight of ihe sled^je, ?o that a man 

 can move it along the line, like a truck, with great taeility; the 

 coupling F is formed for the purpose of connecting the sledge with 

 the train in the usual way, by means of a jo nt and pin. 



The ret irder or apparatus, when out of action, and connected with 

 a train, is attaclieil to the last carriage, as sli"wn at L ; then tha 

 sledge rides above the rails, and is suspended by the spring pieces 

 B B ; but should an accident happen whicli would stop the train, one 

 of the conductors immediately detaches the retarder, and runs hack 

 with it, and places it 300 or 600 yards behind tlie hroken-down train ; 

 then, should not the engineer of the following 'rain olisi-rve ihe train 

 before him, and stop his engine, the engine would run inlu the retarder, 

 and would become a sledge ; the driving wheels, if not slopped by the 

 great resistance which would now be opi'osed to them, would skid 

 round in Ihe retarder, and would have no power tu move forward?. 

 No violent concussion would take place, but the engine would slide 

 along a certain short distance in the retrirder when the train would be 

 brought to a stand-still ; a hanging frame, K, must he fir • ed from the 

 engine frame, and tlie buffers usually placed upon the b' ad board 

 transferred to the lower frames, or other buffers I, placed (here. As I do 

 not consider it would be the best plan to make ilie su|ieriiir end of tha 

 retarder. A, so high as to meet the buffers placed on the head board in 

 the usual manner, the flange of tlie sledge A may lie either continued 

 all along, as drawn, or may be made in detached (lieees at certain 

 intervals in the length, as may be found the best. In the ease of a swift 

 tr.dii overtaking a slow oae in a fog or at night, the swift engine 



