April 20, 19.1.1] 



NATURE 



259 



labour to collect this information. To all those who are 



engaged in water schemes perusal of the paper cannot fail 



to be of interest, but it will probably cause disappointment 

 ■ to find how little information as regards water is available 



in the United Kingdom in comparison with that available 



in some other countries. 



The author concludes his paper by suggested lines of 



organisation in this country so as to have all matters 



relating to water administration under one central 

 luthority. It will probably take some time before such a 

 .implete organisation as is suggested can be attained, but 

 here is no reason why some of the smaller suggestions 



-hould not be carried out at once. We feel sure that if 

 le importance of the question were fully brought before 

 ;ie present President of the Local Government Board he 

 vould be able with very little expense and without a large 



-iipply of red tape to deal quickly with such suggestions 

 > annual returns from all water-supply and sewage- 

 lisposal authorities, and the beginning of a hydrographic 

 -iirvey. If a start were once made and the importance of 

 iie niatter realised, the larger details of organisation would 

 ;radually evolve themselves. 

 The author has added to his paper some tables dealing 



with the use of water in various countries, and there is 

 liso a useful bibliography. M. F. 



THE COMPOSITION OF PINE WOOD. 

 A MONOGRAPH on the " Chemical Composition of 

 ■^^ Pine-wood," by Prof. Klason, of Stockholm, has 

 been issued by Gebriider Borntraeger, of Berlin, as the 

 - cond of a series of " Schriften des N'ereins der Zellstoff- 

 nd Papier-Chemiker." In addition to the importance of 

 J line-wood as the chief raw material of the paper industry, 

 diis particular wood has acquired a special scientific 

 interest from the important colour-reactions in which it 

 has figured as a test material. Thus phloroglucinol 

 imparts a red-violet colour to a pine splinter moistened 

 with hydrochloric acid, aniline sulphate a yellow colour, 

 pyrocatechol and resorcinol a red-violet, pyrogallol a grey- 

 violet, pyrrol and indol a red, phenol a blue, a-naphthol 

 with sulphuric acid a green, hrematoxylin a violet, 

 naphthylamine hydrochloride a yellow, aminoanthracene 

 h\drochloride a red, phenylhydrazine hydrochloride a 

 vllow, and so forth. 



These reactions appear to be characteristic of a sub- 

 lance to which the name of " lignin " has been given; 

 -imilar reactions are shown by the well-known flavouring 

 -ubstance " vanillin," but this is not present as such in 

 ippreciable quantities in pine-wood. Lignin is richer in 

 ( arbon than cellulose, but contains the same proportion of 

 hydrogen ; it differs from cellulose in that it is not dis- 

 ' I by ammoniacal copper oxide, and gives no blue 

 It ion to zinc chloroiodide, but can be reconverted into 

 . . ..ulose by oxidation, and separated from it by dissolu- 

 tion in alkalis or by the action of sulphites, which appear 

 to convert it into soluble sulphonates. The author has 

 analysed the calcium sulphonate, and attributes to it the 

 formula C^„H,,^0,,S,Ca ; this corresponds with a com- 

 position C^„H.,,0,, for lignin itself, but molecular weight 

 iieterminations give values above 4000. In addition to 

 two molecules of sulphur dioxide, lignin combines with 

 two atoms of iodine, and thus contains three double-bonds 

 in the C,„ complex ; four methoxyl groups are present and 

 one hydroxyl group. The substance is probably a con- 

 ii'nsation-product of coniferyl alcohol, 



CII,O.C,H,(OH).CH : CH.CH,.OH, 



(:i substance which (-an be oxidised to vanillin), with an 

 oxyconiferyl alcohol in which the substituents are grouped 

 in the same way (1:3:4:5) as in gallic acid, thus 



2C.„H„0, + 2C,.H.,0,-3H,0= C,.H,,0,.. 



I.ignification appears to consist in embedding the pliable 

 ( ellulose in a hard crust of lignin ; by the action of a 

 sulphite the lignin is dissolved out. and the clean cellulose 

 which is left constitutes the pa|)er pulp. The sulphite 

 • xtracts, from which lignin can easily be recovered, might 

 very possibly prove to be valuable raw material for the 

 manufacture of artificial vanillin. T. M. L. 



RECENT ADVANCES IN TURBINES^ 



(^ N two previous occasions I have addressed this institu- 

 ^"^ tion on the steam turbine. At the time of the first 

 lecture, in 1900, the turbine may be described as having 

 been in the " advanced experimental stage." Six years 

 later it was meeting with " general acceptance " in certain 

 fields. To-night 1 propose to review its progress from 

 1906 to the present time ; but before doing so I shall, 

 with the view of leading up to the subject, and at the 

 risk of some repetition, briefly explain the chief features 

 of interest, and recapitulate some of the earlier steps in 

 its introduction. 



The first turbine of which there is any record was made 

 by Hero^of Alexandria 2000 years ago, and it is probably 

 obvious to most persons that some power can be obtained 

 from a jet of steam either by the reaction of the jet itself, 

 like a rocket, or by its impact on some kind of paddle- 

 wheel. It is, however, not so obvious that an economical 

 engine could be made on this principle. In the year 1888 

 t)r. de Laval, of Stockholm, undertook the problem with 

 a considerable measure of success. He caused the steam 

 to issue from a trumpet-shaped jet, so that the energy of 

 expansion might be utilised in giving extra velocity to the 

 steam. Recent experiments have shown that by such a 

 device nearly the whole of the available potential energy 

 in. the steam is converted into kinetic energy of velocity 

 in a straight line, the velocity attained into a vacuum 

 being about 43,000 feet per second. Dr. de Laval caused 

 the steam to impinge on a paddle-wheel made of the 

 strongest steel, which was allowed to revolve at the 

 highest speed consistent with safety, for the centrifugal 

 forces are enormous. Unfortunately, materials are not 

 strong enough for the purpose (in the large sizes the speed 

 is nearly half that of a rifle bullet), and the permissible 

 speed of the wheel can only reach to two-thirds of that 

 necessary for good economy, as we shall presently explain. 



Dr. de Laval also introduced spiral helical gearing for 

 reducing the enormous speed of his wheel to the ordinary 

 speeds of things to be driven, and we shall allude to this 

 gear later as likely to play a very important part generally 

 in future turbine developments. 



In 1884, or four years previously, I dealt with the 

 turbine problem in a different way. It seemed to me that 

 moderate velocities were essential if the turbine motor was 

 to receive general acceptance as a prime mover. I there- 

 fore decided to split up the fall in pressure of the steam 

 into small fractional expansions over a large number of 

 turbines in series so that the velocity of the steam nowhere 

 should be great, and consequently, as we shall see later, a 

 moderate speed of turbine suffices for the highest economy. 

 This principle is now universally adopted in all except 

 very small turbines, where economy is of secondary import- 

 ance. This arrangement of compounding turbines also 

 appeared to me to be surer to give a high efficiency, 

 because the steam was caused to flow in a non-expansive 

 manner through each individual turbine, and consequently 

 in an analogous way to water in water turbines, where 

 high efficiency at that date had been proved. I was also 

 anxious to avoid the well-known cutting action of high- 

 velocity steam on metal. 



The close analogy between laws for thf flow of steam 

 and water under small diff(>n'iu.s o\ ])v>-^-^\iji- have been 

 confirmed by experiment, and the u>ual U)rmulA= ^2gh, 

 where h is the hydraulic head, gives the velocity of issue 

 from a jet for steam with small heads and also for water, 

 and we shall presently follow this part of the subject 

 further in dealing with the design of turbines. 



Having decided on the compound principle, it was 

 necessary to commence with small units at first, and in 

 spite of the compounding the speed of revolutions was 

 still high. 



Though, as we have said, the de Laval turbine appeared 

 four years later, the de Laval cream separators were in 

 use prior to 1884, and I had the advantage of seeing their 

 beautiful means of balancing — the supporting of the 

 bearings in elastic rubber sleeves, which at 6000 revolu- 

 tions absorbed vibration and allowed the bowl containing 

 the milk to rotate about its centre of gravity instead of 

 its geometric centre. The first compound steam turbine 



' Piscour<e delivered at the Royal Institution on Friday, March to, by 

 the Hon. C. A. Parsons, F.R.S. 



NO. 2164, VOL. 86] 



