558 



NA TURE 



[Oct. 4, 188; 



the Indus valley was filled with those extensive lacustrine and 

 fluviatile deposits, mixed with large angular debris, such as we 

 see at Scardo, which may be coeval with the extreme extension 

 of the Alpine erratics so far as the miocene bills south of Turin. 

 The second period followed after a long interval of denudation 

 of the same beds, and would correspond with the last extension 

 of the great moraines of Ivrea, Maggiore, Como, &c, followed 

 by a final retreat to nearly present smaller dimensions. Nowhere 

 on the south of the Himalaya do we find valleys presenting any 

 features similar to those of the Southern Alps, particularly on 

 the Italian lakes, which are, I believe, the result in the first 

 place of marine denudation, succeeded by that of depression, and 

 tnially powerful ice-action. On the south face of the Khasi and 

 l.untia Hills, however, which are orographically connected w'th 

 the peninsula of India — the conditions altogether different— \ e 

 find long stretches of water of considerable breadth and depth 

 extending within the hills, and not unlike in miniature the Italian 

 lake-. '1 hese valleys, worn out of the sandstone and limestone 

 rock, have been formed here, I think, to some extent by the aid 

 ■ if marine action, and the subsequent depression along this line 

 of hills, also marked here, as in the Western Bhutan Doars, by 

 the absence of beds newer than the nummulitic. 



This attempt to bring before you some of the great changes in 

 the geography of Europe and Asia must now be brought to an 

 end. It is a subject of vast time, of absorbing interest. I am 

 only sorry it is not in more able hands than mine to treat it in 

 the manner it deserves, and in better and more eloquent language ; 

 but it is a talent given to but few men (sometimes to a Lycll or 

 a Darwdn) to explain clearly and in an interesting form the great 

 and gradual changes the surface of the earth has passed through. 

 The -tudy of those changes must create in our minds humble 

 admiration of the great Creator's sublime work, and it is in such 

 a spirit that I now submit for your consideration the subject 

 of this address. 



SECTION G 



MECHANICAL SCIENCE 



Opening Address by James Brunlees, F.R.S.E., F.G.S., 

 Pres. Inst.C.E., President of the Section. 



The British Association for the Advancement of Science 

 admits to its annu-1 gathering women as well as men ; and I 

 venture to think it does so wisely. Women now take their place 

 regularly in the ranks of several scientific professions ; and 

 though they have not shown any desire to enter that to which I 

 belong, there has recently been an example of their capability in 

 that direction which is noteworthy. It has been publicly stated 

 that Col. Roebling, the distinguished engineer of the Brooklyn 

 suspension bridge, which is one of the most remarkable works 

 of the age, was assisted during a long illness in carrying out his 

 work by the talent, industry, and energy of his wife, who ac- 

 quired theoretical and practical knowledge enough to aid in 

 seeing that her husband's design was properly carried out. I 

 think this example is not unworthy of mention here, as honour- 

 able to the individual woman, to the energetic nation to which 

 she belongs, and to the better half of the human race. 



The previous meetings of the British Association have been 

 held in places possessing very varied characteristics ; but in none 

 in which the pursuits of science could be undertaken under more 

 pleas ng circumstances than in Southport, with which I have 

 been acquainted for a good many years. 



It is customary for the President of each Section to begin the 

 Session by giving an introductory address. I propose, with your 

 kind indulgence, to offer some brief remarks, as far as possible 

 free from technical language, on a subject which is familiar to 

 my own mind, and within my own experience, during a period 

 now approaching half a century, that is : The growth of 

 mechanical appliances for the construction and working of rail- 

 ways and docks. 



The railway of the present day is in principle what it was at 

 the outset j but it differs in detail from the original railway as 

 much as, or more than, the skewer which fastened the dresses of 

 the ladies of Elizabeth's time from the pin of the present day, 

 or the carpets of this era from the rush-strewn floors of that. 

 The 1 rogress has been gradual, but not slow. From the open- 

 ing of the first railway to the present date is only a period of 

 about sixty years, and in that short time Great Britain and 

 Ireland, the continent of Europe, America, North and South, 

 India, Australia, and Africa, have been pretty well supplied with 



railway lines, more and more perfect in construction, and in a 

 degree more or less suitable to the needs of their populations. 



About thirty years ago, when the traffic on railways had been 

 very largely developed, the parts of the permanent way which 

 had at first been thought likely to be the most enduring, the 

 rails themselves, were f- »und to be more rapidly worn away than 

 was expected. Efforts were made to harden the surface of the 

 rails, and a plan was introduced by Mr. Dodds for this purpose. 

 It was extensively used where rails were subject to special wear 

 and tear, at points and crossings. The conversion was easily 

 effected : it cost only about fourteen shillings to a pound a ton, 

 and it was estimated that it doubled the durability of the rails. 

 If they were turned, of course it increased their durability three 

 times. 



The plating of rails with a steel surface was probably begun 

 about 1S54. It was not till about eight or ten years later that 

 rails were made entirely of steel. 



In May, 1S62, steel rails were laid down experimentally at 

 Chalk Farm Bridge "side by side with two ordinary iron rails, 

 and after outlasting sixteen faces of the iron rails they were 

 taken out in August 1S65, and the one face only which had been 

 exposed during a period of more than three years to the enormous 

 traffic, amounting to something like 9,550,000 engines, trucks, 

 &c, and 95,577,240 tons, although worn to the extent of a little 

 more than a quarter of an inch," even then appeared capable of 

 enduring a good deal more work. Steel rails, however, were 

 dear at that period, costing about double (ill. 10s. per ton) as 

 much as iron rails ; therefore, although their advantages were 

 manife t, they could not all at once replace iron. In 1866, Mr. 

 Webb, the locomotive engineer of the London and North- 

 western Railway, said they had in use 3000 tons of steel-headed 

 rails and about fifty miles of steel rails ; and Mr. Harrison, of 

 the North-Eastern, said he had just contracted for 500 tons. 

 Now, owing to improvements in the manufacture of steel rails, 

 they can be produced as easily and as cheaply as iron rails. It 

 was observed in 1S76 that if, in order fully to realise the effect 

 of the enduring quality of steel rails, you take a given section of 

 the busiest portion of one of our leading railways, over which 

 upwards of 7,000,000 tons of live and dead weight pass 

 annually, you would find that the life of a steel rail on that por- 

 tion of the line would be forty-two years if the traffic remained 

 the same. This would reduce the cost of maintaining the per- 

 manent way of railways from 210/. to 106/. per mile. When 

 you consider that such a saving on a system of 500 miles, which 

 at 25,000/. a mile costs twelve and a half millions, is 52,000/. a 

 year, or about a half per cent, of the cost of the railway, you 

 will see that, besides some increase of dividend to shareholders, 

 no inconsiderable sum may be, and has been, devoted by the 

 railway systems of Great Britain to the comfort of travellers out 

 of the saving effected by the introduction of steel rails. 



You are aware that railways are worked by the aid of an 

 elaborate system of signals, by which those in charge of a train 

 are required to be guided in regard to its movements. The 

 author then gave a history of signals, bringing his account down 

 to the present day. 



The subject of brake power is one to which very great atten- 

 tion has been given both in this country and abroad ; and cer- 

 tainly, next to the condition of the permanent way and the 

 efficiency of the signalling apparatus, perhaps nothing in con- 

 nection with railways is of greater importance. Many lives and 

 much property are hourly dependent in a greater or less degree 

 on the power and efficient state and immediate action of brakes. 

 It has been found that most of the collisions which have occurred 

 might have been prevented had those in charge of trains pos- 

 sessed the power of stopping them within a few hundred yards. 

 The higher the speed and the heavier the train, the greater the 

 necessity for a powerful and simple brake, capable of being 

 applied throughout the train in the shortest possible time. 



All recent efforts for the improvement of brakes appear to 

 have been devoted to making the action of the brakes automatic, 

 and to increasing the rapidity with which they can be applied. 



I do not intend to enter into the controversy respecting the 

 best system in use for obtaining these results. There are several 

 systems by which they are attained more or less effectively ; and 

 whereas trains which thirty years ago weighed on the average 

 thirty tons, with engines of the same weight, running at thirty- 

 live miles an hour, could scarcely be brought to a stand in a 

 distance of about jjoo or 1000 yards, now trains of twice or three 

 times that weight, and running at a much higher speed, can be 

 brought to absolute rest in twenty or thirty seconds, and within 

 a distance of from 300 to 400 yards. 



