March 26, 1885] 



.V. 1 TURE 



497 



obtained salmon eggs and milt from fish captured in the Teith, 

 and which ova hatched in March, 1SS1. In July, 1883, it was 

 seen that some of the young salmon, then two years and four 

 mi tilths old, were either in the parr livery or had assumed the dress 

 of silvery smolts, the latter in certain lights showing parr bands. 

 On November 7, 1884, a smolt l| lbs. weight jumped out of the 

 pond, and from it about 100 eggs were expressed, and as they 

 seemed to be ripe they were milted from a Lochleven trout. — 

 On January 23, 1885, eighteen of these eggs hatched ; the 

 young were strong and healthy. November n, 18S4, about 

 12,000 Lochleven trout eggs were milted from one of the 



-molts, and they hatched January 2S, 1885. De- 

 cember I, 1884: 1500 eggs were taken from two of the fore- 

 going smolts, and treated by the milt of one of the males. On 

 the 9th, about 4000 eggs from these smolts were fertilised from 

 one of the males, and on the 13th, 2500 smolt eggs were milted 

 from a parr. Dr. Day further stated that pure salmon eggs in 

 the Howietoun Fishery have been hatched, that the young have 

 grown to parr, smolts, and grilse ; that these latter have given 

 eggs, and their eggs have been successfully hatched. Although 

 time will yet be necessary before a definite reply can be given 

 as to how these young salmon will thrive, how large they will 

 eventually become in fresh water ponds, and whether from them 

 a land-locked race may be expected — still the following points seem 

 to be established. That male parrs or smolts may afford milt 

 capable to fertilise ova ; but, if taken from fish in their second sea- 

 son at thirty-two months of age, they are of insufficient power to 

 produce vigorous fry. That female smolts, or grilse, may give eggs 

 at thirty-two months of age, but those a season older are better 

 adapted for the production of vigorous fry, where, to develope 

 ova, a visit to the sea is not a physiological necessity. That young 

 male salmon are more matured for breeding purposes than are 

 young females of the same season's growth. That female sal- 

 monida; under twenty-four months of age, although they may 

 give ova most, are of little use for breeding purposes, the young, 

 if produced, being generally weak or malformed. That at 

 Howietoun, so far, hybrids between trout and salmon have 

 proved to be sterile. Furthermore, it was stated that the size of 



lmonidse vary with the age and condition of the parent, 

 but as a rule older fish give larger ova than younger mothers. 

 Even among the eggs of individual fish, variations occur in the 

 size of the ova. From larger ova finer and rapidly growing fry 

 are produced, consequently by a judicious selection of breeders, 

 races may be improved, but it is only where segregation is effi- 

 ciently carried out that such selection is possible. — A paper was 

 afterwards read, Notes on some recently-discovered flowering 

 plants from the interior of New Zealand, by the Rev. W. Colenso. 

 In this the author describes and gives field notes on some 

 eighteen supposed new species. 



Institution of Civil Engineers, March 3. — Sir Frederick 

 I. Bramwell, F.R.S., President, in the chair. — The paper read 

 was on the construction of locomotive engines, and some results 

 of their working on the London, Brighton, and South Coast 

 Railway, by William Stroudley, M.Inst.C.E. The author, on 

 his appointment to the London, Brighton, and South Coast 

 Railway, in 1870, had to consider what kind of locomotive 

 engine and rolling stock would best meet the requirements of 

 the service ; as, owing to the great increase and complication of 

 the lines and traffic, the original primitive engines and rolling 

 stock were not able to do so. He, therefore, in the same year 

 designed a large goods engine, class "C," arranging the detail 

 so that they would enable him to construct the several classes 

 illustrated, all the principal parts being interchangeable. 

 Having had long experience with both outside- and inside- 

 cylinder engines, he adopted inside cylinders, but placed the 

 crankpins for the outside rods on the same side of the axle as 

 e crank, the outside pin, however, having a shorter 

 stroke ; and he thus obtained the advantages of both systems. 

 ted the method of putting the coupled wheels in front, 

 instead <.f at the back as usual, which permitted the use of small 

 trailing wheels, lightly weighted, and a short outside-coupling 

 rod for the last running engines, and also a much larger boiler 

 than could be obtained when the coupled wheels were at the 

 back. The author adopted a somen hat high centre of gravity, 

 believing that it made the engine travel more easily upon the 

 mad, and more safely at high speeds ; the slight rolling motion, 

 causi I by the irregularities of the road, having a much less 

 disturbing influence than the violent lateral oscillation peculiar 

 to engines with a low centre of gravity. The high centre of 



gravity also threw the greatest weight upon the outside or 

 guiding wheel when passing around curves ; and this relieved the 

 inner wheels, and enabled them to slip readily. The author 

 used six. wheels in preference to a bogie for these engines, to 

 avoid complication and unnecessary weight. The engines were 

 very light for their power. Spiral springs were used for the 

 middle axle, and these had a greater range than the end ones 

 for the same weight. The two cylinders of the large engines 

 were cast in one piece, with the valves placed below, giving 

 lightness, closeness of centres, and easy exhaust and steam- 

 passages. The crank-axle was the only disadvantage left in an 

 inside cylinder, inside framed engine, and, when this was of 

 good proportions, it offered but a small objection. Owing, 

 however, to the narrow gauge of the rails in this country, the 

 crank-axle could not be made so strong as it ought to be, or 

 there would be no reason why a crank-axle should break. 

 When the flanges of the driving-wheels were turned down thin, 

 so as to avoid the side-shock given by crossings and check-rails, 

 there only remained the strain of the steam upon the pistons to 

 cause breakage ; the action of this was precisely the same as 

 the methods used by the late Sir William Fairbairn in testing to 

 destruction the model tube for the Menai Bridge, by letting a 

 heavy weight rest upon it suddenly at frequent intervals. The 

 deflection, if sufficient, caused a crack at the weakest place, 

 which gradually extended until fracture took place. This was 

 precisely what occurred in the axle ; the crack invariably com- 

 mencing on the side of the axle opposite to that to which the 

 steam was applied. The author, after thirty years' experience, 

 believed that the separate parts of locomotives, including tires, 

 axles, piston-rods, side-rods, bolts, cotters, and carriage and 

 wagon axles, broke from the same cause ; they did not break 

 when carefully designed, and made with proper materials and 

 workmanship. As the crank-axle could not be made of the 

 proper strength, it was well to consider how to avoid, as far as 

 possible, risk of accident by its failure. By making the axle- 

 boxes and horn blocks deep and strong, giving large flat sur- 

 aces against the boss of the wheel and the outside of the crank 

 arm, the driving-wheel was kept in position after the axle was 

 broken, if the fracture occurred in the usual place, namely, 

 through the inside web, near the crankpin, or through the 

 centre part where it joined the inside web. An axle, broken in 

 this manner, would run safely over any part of the road, 

 except at a through-crossing, where the guiding-rail was lost, 

 and the flange was liable to take the wrong side of the next 

 point ; this, however, had not happened in the author's experi- 

 ence. The author had always hooped the larger cranks, and 

 had for some time hooped every new crank in the same propor- 

 tion as adopted on the Great Northern Railway, thus reducing 

 the risk to a minimum. The engines had been arranged that 

 part of the exhaust steam might be turned into the tender or 

 tanks, so that the feed-water might be heated. This was a 

 special advantage in a tank engine, by increasing the total 

 quantity of water ; it also kept the water supply of greater 

 purity, and it relieved the boiler of a certain amount of duty in 

 heating the water from the ordinary temperature to that which 

 feed-water required. The feed-pumps had been designed to 

 meet the requirements of pumping hot feed-water. The propor- 

 tions of the valve-gear gave an admission of 78 per cent, of 

 steam in full gear, which could be reduced to 12 per cent, with 

 excellent results ; and as at high speeds the steam was never 

 exhausted, the temperature of the cylinder was maintained, and 

 as much steam was locked up in the cylinders as raised the 

 pressure at the end of the stroke to near that in the steam chest. 

 This made the engine run very smoothly at high speeds, and 

 turned what would otherwise be an extravagant coal-burner into 

 an economical machine. And for the same reason the com- 

 pounding of fast-passenger or frequent-stopping locon otives 

 was not likely to show much, if any, economy over a well- 

 designed, simple engine. The case was different, however, in 

 heavy goods engines, working with a late cut-off most of the 

 time, and where the conditions approximated closely to those of 

 a land or marine engine with a constant load. The back-pressure 

 observed in the diagrams of high-speed locomotives was not 

 therefore a defect, but an advantage, and the author accordingly 

 used small steam-ports and short travel of slide-valve. These 

 remarks as to back-pressure did not apply to the pressure in the 

 exhaust pipes, where it should fee as small as pos ible, but only 

 to the back-pressure in the cylinder. The latter was greatest at 

 high speeds, when a small volume of steam was passing through 

 the cylinders, and small power was required, and least when 



