September 30, 1S97] 



NATURE 



\2\ 



reaction increases the rotational force. The same pro- 

 cess takes place at each of the successive rings of guide 

 and moving blades. The energy to give the steam its 

 high rotational velocity at each successive ring is sup- 

 plied by the drop in pressure, and the steam expands 

 gradually by small increments. In a moderate-sized 

 turbo-motor there may be from thirty to eighty successive 

 rings, and when the steam arrives at the last ring the 

 expansion has been completed. On the left side of the 

 steam inlet J are the driving or rotating pistons, which 

 are fixed to and rotate with the shaft. On their outsides 

 are grooves and rings, which project into corresponding 

 grooves in the case. Hy means of the thrust bearing of 

 the motor the longitudinal position of the shaft is adjusted 

 and grooves and projecting rings kept nearly touching, 

 so as to make a practically tight joint. The object of 

 these pistons is to steam balance the shaft and relieve 

 end pressure on the thrust bearing. Fig. 3 shows a 350 

 kilowatt turbo-alternator, thirteen of which size are now 

 at work in the London stations. 



With compound condensing turbines a steam efficiency 

 comparable with the best compound or triple expansion 

 condensing engines was at length reached, and it was 



of yi\ knots, and the maximum speed so far obtained 

 has been about 35 knots. 



It is anticipated that this turbine engine can be success- 

 fully applied to all the faster class of vessels, including 

 those of the largest size ; in fact, it appears that the 

 relative advantages are greatest in the largest sizes. 



NOTES. 

 The new Government Lalxiratory, which has been about two 

 years in course of erection, is now completed, and will be 

 formally opened to-morrow (October i). We hope to be able 

 to give a description of the building in our next issue. 



The Paris correspondent of the Times states that an anni- 

 versary service was held on Tuesday at the Pasteur Institute in 

 honour of the great investigator. A number of his disciples and 

 the members of his family who are in Paris assembled in the 

 crypt of the Institute at his tomb, and placed upon it garlands 

 of flowers from the (Marches gardens. The subscription for the 

 Pasteur monument now exceeds 300,000 francs. 



then resolved to test the application of the turbine to the 

 propulsion of ships, for which purpose it seemed well 

 suited, provided that as good an efficiency could be obtained 

 from fast running screw-propellers as with ordinary ones, 

 and to test the system it was determined to build the 

 Titrhinia, which is 100 feet in length, 9 feet beam, and 44^ 

 tons displacement. One compound condensing turbine 

 engine of 2000 I. H. P. was at first fitted, but it was found 

 that long before this power was developed the screw 

 began to tear the water, forming vacuous spaces and 

 vortices behind the blades, and causing great loss of 

 propulsive effect. The single large engine was then 

 replaced by three separate ones, high pressure, inter- 

 mediate pressure, and low pressure, each driving a screw- 

 shaft at the same speed of rotation as before ; but the 

 blade area was by these means trebled, and this trouble 

 ceased. The efficiency of the screws approached closely 

 to the best results of ordinary screws. The Turbinia!s 

 engines are similar to those for the driving of dynamos 

 described, but they are necessarily larger and of lighter 

 construction, and the expansion of the steam is carried 

 to 1 70- fold at full speed. Prof Ewing's tests have shown 

 a consumption of 14J lb. of steam per I.H.P. at a speed 



NO. 1457, VOL. 56] 



An epidemic of typhoid fever has broken out at Maidstone, 

 Kent. More than nine hundred cases have been notified, 

 and up to Tuesday night twenty-one deaths from the disease 

 had occurred since the beginning of the outbreak. The epidemic 

 is due to polluted water, and is confined to the area of the town 

 supplied with water from springs at Farleigh, all of which have 

 been condemned by the medical officer of health. 



It is much to be regretted that the splendid male Giraffe, pre- 

 sented to the Queen by the Chief Bethoen, of Bechuanaland, 

 died so soon after reaching this country. The difficult task of 

 bringing it home was entrusted by the Colonial Office to the 

 Zoological Society, who selected for the work one of the most 

 experienced men in Europe in moving large living animals — Herr 

 Windhorn, of Alfeld. The Giraffe was led from Kanya to 

 Lobatsi by road, and safely lodged at the railway station in a 

 box, which had been specially constructed for it at Cape Town. 

 It was placed on board the s.s. Roslin Castle (in which a free 

 passage had been most liberally granted to it by Sir Donald 

 Currie), and left Cape Town on September i. The passage was 

 a stormy one, and after the first week the Giraffe declined to eat 

 anything but bread. A few days later it left off feeding altogether, 



