582 



NA TURE 



[October io, 1895 



on ail all but empty room. Another cause of complaint on the 

 |iart of members of this Section was that the second Wednesday 

 was a dits non. Doubtless verj- few object to a w hole holiday at 

 these meetings, but what people do find fault with is that they 

 should be kept hard at work on Saturday, » hen there are pleasant 

 excursions, to be turned adrift on Wednesday. Of course one 

 can go home and cut the business short, and that is what many 

 do, and the Thursilay's excursions thus suffer. Indeed a con- 

 scientious member, determined to do his Section ll thoroughly, 

 was unable to go to any of Saturday's excursions, and would 

 have to spend an idle day waiting for the Thursday's excursions. 

 The excursions are the great feature of the .•\ssix:iation meetings, 

 as they bring meml>ers together and make them known to each 

 other in a way that no other institution or si>ciety does. 

 Possibly more has been done for the Advancement of Science by 

 such means than by the meetings of Sections, for there are other 

 associations which afford op|x)rtunities for the reading and dis- 

 cussion of i>a|)ers, but none which offer the same social facilities 

 as the British Association. When it is remembered that only 

 two Sections met on the second Wednesday, it is a question 

 whether it would not be of advantage to make it a rule to 

 fix the whole day excursions for Wednesday instead of Thurs- 

 day. We are aware that this would create difficulties in regarti 

 to meetings of general committees, but surely these could be 

 overcome. 



The I'resident of Section G this year was I'rof. L. K.Vernon- 

 Harcourt, who opened the j)roceedings of the Section by reading 

 his presidential address. 



The first paper taken was a contribution by Major-Gcneral 

 Webber, on light railways as an a.ssislance to agriculture. 

 It ciintained the main elements of a scheme which the author 

 had thought out for introducing a system of light railways in 

 Suffolk. A good deal of attention was given to the subject of 

 gauge, which the author considered should be narrower than the 

 standard gauge of the country, viz. 4 ft. S.J in. There is much to 

 be said in favour of a narrow gauge for auxiliary railways, but 

 alsf) much to \k saiil against it. No doubt a narrow gauge is 

 chea|)er than a wider one, but i)erhaps not so much cheaper 

 as m.iny [lersons imagine. Sharper curves can also be taken 

 with a narrow gauge, and it can be laid in position where 

 often the brtiader gauge would necessitate the widening of the 

 road. On the other hand, the standard gauge enables the waggons 

 and trucks of the trunk lines to l>e run nn the auxiliary railways. 

 It may be said that a light railway demands — on the score of 

 cheapness — that the road bed shall l>e of a less substantial 

 character than that of the trunk lines ; but here it is essential to 

 bear one fact in mind. The massi\e permanent way of our trunk 

 lines is required for the heavy locomotives running at high speed. 

 With small engines and com|)aratively slow speed very light per- 

 manent way will carry the ordinary railway go<Kls stock with 

 safety. The first thing, however, which has to be done in order 

 to facilitate the introduction of auxiliary railways in this couniry, 

 is to give power to the Board of Trade Io relax its own regula- 

 tions. 



A |Kipcr by M. A. Oobert, of Brussels, on a freezing process 

 for shaft sinking, was next read. In general principle the 

 suggestion is not new. In cases where water-bearing strata is 

 encountered in shaft-sinking, a freezing medium is caused to 

 circulate in pi|>cs. The vehicle used is ammonia, which, 

 ev.Tjwirating in the pipes, produces the freezing effect. 



"I'he next [a|»er read was of considerable interest ; it was a 

 memoir by .Mr. W. II. Wheeler, of Boston, on the effect of 

 wiiiil .ind almr»pheric pressure on the tides. I'or many years )>ast 

 the author h.as lieen making observati<ins on this subject. Krom 

 an analysis of twn years' tides at the I'ort of Boston, (excluding 

 iH-rasions when the element of wind would affect the c.i.se), he 

 found that out of 152 oljservalions, Ol gave results oppisile 

 to that which would have been ex|)e<ted by the readings of the 



' '■ r alone ; for a high barometer was frequently 



•d by a high tide, and a low larometer by 



On the other hand it w.is found, with few 



. that when the wind blows with any force along 



■I Ihi- same direction as the main sirean) of the 



'\\ the ports along the iiiasi will be 



' height given in the tide-laltles ; and 



...-. .* ,.,.irii.l the flood tide, high. water will \k 



caUulalcd. According to figiiies quoted in the 

 effect of wind is such as to affect the tide as 

 to 6 feel, and a rliffercnce of as much as 8 



I'lwer than 

 |>.i|H'r, the 

 niuili as 5 

 fc^ 



has l)cen oliscrved lielween two succeeding tides. 

 NO. 1354, VOL. 52] 



An analysis of the register of tides at Boston Dock for 

 two years showed that 24 |ier cent, of the whole tides recorded 

 were sufficiently affected by the wind to vary 6 inches from the 

 calculated height. Thirty varied by 2 feet, seven by 3 feet, six 

 by 3i feet, three by 4 feet, two by 4^ feet, one by over 5 feet, 

 and one by 6 feet 3 inches. From the observations he has made, 

 Mr. Wheeler has deduced the approximate rule that with a given 

 force of wind of 3 on the Beaufort scale a tide will be raised or 

 depressed by half an inch for every foot of range. With a force 

 of from 4 to 6, the variation may Iw expected to be i inch for 

 every foot, with a gale from 7 to S it will l>e \\ inches, and if 

 the gale increases to 10 it will Im; 2 inches. It will lie seen that 

 the subject is one which iwssesses not only scientific interest, but 

 considerable practical importance to n^ariners ; anil so far as we 

 are aware. Mr. Wheelei is the first who has ol)taineil quantitative 

 results of this nature. In the discussion which followed, it was 

 jxiinted out that the time element would have to be given its 

 due value. 



At the second sitting of the Section, on l-'riday, the 13th ult., 

 Mr G. J. Symons gave what was really a lecture on the autumn 

 floods of 1894. This contribution was discussed together with 

 a jxaper by Sle.ssrs. Kapier and Stoney, on weiis in rivers. 

 Any contribution by Mr Symons is sure to meet with a good 

 reception at a meeting of the Association, and Mr. Stoncy's 

 work in connection with river engineering is also so well kn*)wn, 

 that it was not surprising that the attendance in the Section should 

 be a full one when the sitting openeil. The floods of November 

 of last year, it will be remembered, were of an unusually severe 

 character, a gieat jxart of the low-lying lands of the Thames 

 Valley Iwing submerged. The meteorological conditions which 

 led to these floods were traced by -Mr. Symons, and the eflects 

 stated. With regarti to the latter, it would be but to repeat a 

 long histor)' of floodeil homes, spoiled furniture, and general 

 damage to property. The extent of course will never be known, 

 but it was sufficient to be accounted a calamity of considerable 

 magnitude. There were two periods of heavy rainfall quickly 

 succeeding each other, but it was the secontl which was the 

 immediate cause of damage ; the first, if it had stood alone, would 

 have been comjwratively inm'icuous. The first period occurred at 

 the end of OctolK'r, ami nearly all the additional land water caused 

 by it had pa.ssed over I'edilington Weir before the second period 

 arrived. The November rains, however, found the earth well 

 saturated, and the water that fell ran therefore almost wholly 

 into the river l)ed, with the unfortunate results before referred 

 to. The moral Mr. Symons chiefly strove to impress was the 

 necessity of automatic records and communication between 

 difl'ereni divisions of a water-.shed, so that prompt warning might 

 be given of a probable flooti. Such precauti^ins are taken by 

 c(mtinental nations, but in linglaiui they are sadly neglected. 

 The necessity for obtaining accurate data, and treating it in a 

 systematic and scientific manner by tiained observers, was well 

 illustrated by instances given ; for example, the river Mole was 

 at its highest four days before the Thames, and if the warning 

 thus given by nature had been heeded, much of the damage 

 which followed might have been prevented. 



The seciind paper gave a goml description of the movable 

 weirs which have become identified with Mr. Sloney's name, 

 and which were so prominently brought before public notice in 

 coimection with the .Manchester Ship Canal. A more recent 

 example, and one which is better knowit to Londoners, is that at 

 Kic'hmond, where there is a half-tide lock and a series of lifting 

 weirs. It has been claimed that if many of the fixed weirs in 

 the Thames were removed, and these lifting weirs substituted for 

 them, that there wouhl be less danger from flooding of the river. 

 How far Messrs. Kapier and .Stimey go in this direction we did 

 not gather from the paper, but such we took to be the general 

 drift of their argument. The position was disputeil during 

 the discussion which fnllowed, it being ntaiiilaiiiecl by some 

 speakers that even if the flow of water were absolutely unim- 

 peded as far .as Tc<l<lington Weir, the tidal portion of the river- 

 channel is not of sufficient section to carry ofl' all water th.il 

 comes down in time of heaviest rainfall. The question is com- 

 plicated by the ebb and flow of the tide, but it ought not to be 

 nnpossible to arrive at a fairly definite conclusion. The matter 

 is one which wants investigation by a competent authority, for 

 wcdid not notice that any more than general statements were made 

 in support of the alleged insufliciency of the tidal ch.innel : an<l the 

 sl.atements, therefore, did not appear to rest on a substantial b:isis 

 of fact. The problem of the utilisation of the heail ol water 

 at the weirs in the Thames w.as also brought forward. W itboul 



