492 



NATURE 



March 22, 1894 



every point of the immersed surface of a ship, upon the lines 

 and speed being given, is one which will long remain to be 

 solved ; but every step towards that end must be of interest, 

 and the best way to proceed is naturally to divest the subject of 

 ;hose elements which tend to obscure its solution, and thus 

 grapple with difficulties in detail. This the author proceeds to 

 do by imagining a set of conditions which by no means exist. 

 Thus, he supposes the surface of the water covered by rigid 

 smooth ice, and the vessel to be flat-bottomed with vertical 

 sides. In this way similar water lines are obtained, and the flow 

 of wa':ei» will be in plane stream lines only. This simplifies the 

 work, since the methods and formulae dealing with stream lines 

 in two dimensions are much simpler than those for stream lines 

 in three dimensions. The author proceeds to work out his 

 problem on these lines at some 'length, and it will be evident 

 from what has been said that it would be impossible to deal 

 adequately with the question in a report such as this ; in fact, 

 the paper requires more study than we have been able to give 

 to it up to the present, . A short discussion followed the 

 reading. 



Mr. Stromever's paper discussed steam pressure losses in steam- 

 engines due to various causes, such as friction of steam in pipes 

 and passages ; the spring of eccentric straps, rods, and links ; 

 inaccuracies in slide valve motion ; piston leakage ; throttling of 

 steam, &c. Mr. Croll's paper dealt with a subject that has oc- 

 cupied the attention of marine engineers for some time past — the 

 best method of working engines at lower powers ; and Mr. Joy 

 described his arrangement for reversing engines by means of an 

 hydraulic cylinder placed inside the eccentric, so that an 

 effect, in some respects, similar to that obtained by means of the 

 loose eccentric is reached without the uncertainty of the latter 

 device, and also with the further benefit of being able to " link 

 up " or to stop the engines by making the eccentric disc coaxial 

 with the shaft. The arrangement is certainly a very taking one, 

 and appears to promise well, though of course such a tried de- 

 vice as link motion will not be ousted until any new arrangement 

 has thoroughly proved its superiority. 



The meeting terminated with the usual votes of thanks. The 

 summer meeting will be held at Southampton, in July. 



CHOLERA} 



TF anyone had undertaken, thirty years ago, to classify th^ 

 •^ communicable diseases according to whether they are easy 

 or difficult of prevention, he would have doubtless placed 

 cholera, the disease I have chosen for the subject of this lecture, 

 in the front rank amongst the non-preventible, or, at any rate, 

 amongst those diseases that are preventible with very great 

 difficulty ; while, if anyone were at the present time to revise this 

 classification, he would find himself in the fortunate position of 

 placing cholera in the front rank amongst those diseases that are 

 easily prevented ; in fact, he would be able to tell you that the 

 prevention of the spread of cholera is beset with less difficulty 

 than that of some of the communicable diseases which in towns 

 we have almost constantly among us, as, for instance, pneu- 

 monia, diphtheria, measles, and scarlet fever. Nothing could 

 more forcibly illustrate the great advance in practical sanitation 

 than the comparative immunity from cholera in an epidemic 

 form, which this country has enjoyed for the last twenty- five 

 years. By saying "comparative immunity," I am not forget- 

 ting that we have had cases of Asiatic cholera in this country 

 during the last autumn, and it is precisely the remarkably limited 

 character of this last outbreak which furnishes the best proof of 

 our advance in sanitation, and gives satisfactory evidence of the 

 correctness of the views on which the measures adopted for 

 the prevention of the spread of cholera are based, and of the 

 justification of placing cholera amongst the easily preventible 

 diseases. To give you an idea of what sanitation has been able 

 to do, and the complete success which attended the practice of 

 good sanitation in preventing the spread of cholera, I will quote 

 in illustration the following remarkable instance:" — A well- 

 known fact which has received, unfortunately, a great many 

 illustrations, is this : that pilgrims in India carry the contagium 

 of cholera from the fairs or festivals, to which the disease 

 is brought from the endemic area, to localities which were 



' A Lecture delivered at the London Institution on February 15, 1S94, by 

 Dr. E. Klein, F.R.S. 



2 This account is taken from Mr. Ernest Hart's description in the 

 Daily Graj>hic, September, 1893. 



previously free from cholera. One such fair is particularly 

 notorious, and it has in the past always been a source of the 

 utmost anxiety to the Government of India ; this is the great 

 religious festival or Kumbh fair of tiardwar, a town on the 

 Ganges, but situated outside the endemic area of cholera. This 

 great Kumbh occurs once in twelve years, and it is attended by 

 large numbers of pilgrims, a proportion of these coming from 

 districts in which cholera is always endemic, tt has thus fre- 

 quently happened that this great concourse of pilgrims has been 

 followed by a wide diffusion of the disease. The great Kumbh 

 is principally a religious festival, and is looked upon by Hindus as 

 one of peculiar sanctity, and the very aim and object of their 

 pilgrimage is to bathe in the sacred Ganges, and drink of 

 its holy waters. In 1891, when the last Kumbh fair was held, 

 800,000 to 1,000,000 pilgrims assembled in Hardwar ; and to get 

 an approximate estimation of the enormous pollution to which 

 the sacred Ganges at Hardv\ar is on this occasion subjected, and 

 the great risk from cholera to which those who drink of its 

 waters are exposed, I will mention what Dr. Simpson, the able 

 health officer of Calcutta, states. In describing the scene at 

 the " sacred pool " at Hardwar — somewhat retired from the 

 rest of the river — to bathe in which and to drink whose waters 

 the pilgrims gather together in such multitudes, Dr. Simpson 

 states that as the bathing of the pilgrims went on the clear stream 

 became a muddy one ; that from April 8 to 12 there was always 

 passing through the sacred waters a " seething mass of humanity " 

 in constant motion, passing through the pool at the rate of 

 400 to 500 per minute. You can easily picture to yourself that 

 a few cases of cholera introduced into such a rhukitude, living 

 under such conditions, would easily cause not only an outbreak 

 of cholera there and then, but would by the returning pilgrims 

 be carried far and wide. Thus a sanitary commissioner says 

 of the Kumbh, previous to 1867 : " Very little remains on record, 

 but that little is a record of disease and death." In 1867, and 

 again in 1879, the festival was followed by an epidemic out- 

 break of cholera, which on the latter occasion rapidly extended 

 to the western districts. Now, all through the winter of 1890-91 

 there was much cholera in the north-west provinces and along 

 the pilgrim routes below the hills. So grave was the outlook, 

 that the question of prohibiting the fair to be held in April, 189s, 

 was seriously discussed, vn 1 the official opinion of a civil-sur- 

 geon, in conformity w'. iiat of many other officials of great 

 experience, was to the en ( 1 that " the most complete sanitary 

 arrangement will be powerless to prevent the spread of cholera 

 should the contemplated fair at Hardwar be permitted to take 

 place." Now mark what Mr. Ernest Hart says : 



"The fair took place in April, 1891. In December, 1890, 

 proceedings began at and about Hardwar by the construction 

 of seven bridges, by means of which access to the sacred pool 

 from various parts was much facilitated. The whole of the site 

 was then cleared of undergrowth, all filth was scraped away and 

 removed, and arrangements made for the trenching of night 

 soil. A small army of 1342 sweepers was engaged, and means 

 were taken to prevent their desertion, an event which previous 

 experience had shown to be not unlikely. The whole site was 

 divided into sanitary sections, each with its temporary hospital 

 and its sanitary patrol, every constable of which had his own 

 fixed beat, within which he was "instructed to (i) prevent 

 overcrowding, ^2) see to surface cleanliness, (3) give notice 

 and remove nuisances, (4) report offenders, (5) remove those 

 sick of infectious diseases, (6) see to the proper location of 

 animals. The sanitary, police, and medicalsections were made 

 to correspond, each section being equipped with a special hos- 

 pital, a number of constables, sanitary inspectors, an ambulance, 

 and a large staff of conservancy men. Each section was thus 

 complete and self-contained, and was directly responsible to 

 the sanitary and deputy sanitary commissioners for the con- 

 ditions of its own area. The members of the sanitary patrol 

 had each their given beats, over which they exercised a con- 

 stant supervision, acting also as detectives for sickness. 



" The key to the sanitary management of the fair lay in the 

 searching out and rapid removal of all cases of suspicious dis- 

 ease, in the maintenance of perfect cleanliness in the camp, and 

 in the measures taken to prevent all possibility of contamination. 

 Various improvements, however, were made in the conduct of 

 the bathing festival, which were no doubt of great importance. 

 "The pilgrims coming from cholera-infected districts brought 

 the infection with them, and two people died of undoubted j 

 cholera at Hardwar during the most crowded period, but they 

 were promptly isolated, and the infection did not spread. No , 



NO. 1273, VOL. 49] 



