How short-sighted and foolish is it to endeavor to throw discredit on these experiments which were made with the greatest care and honesty and which were witnessed and subscribed to by impartial experts, and to argue that, because other experiments made under different conditions showed a somewhat slower rate of evaporation, therefore cases could never occur in which the more rapid rate might be encountered in practice.
It is likely that the public will very soon awake to a sense of the importance of investigating this matter for themselves. Their Boards of Health will then find that with a very small outlay they can obtain the truth; and that a vast amount of unnecessary complication and expense can be saved in plumbing and, at the same time greater security be obtained.
When we consider, too, the well-known unreliability of the vent-pipe in other ways and the frequency with which it is found totally closed by grease, it becomes something more than folly to recommend the public to place implicit reliance upon it.
J. P. Putnam.
The Divining-Rod.—Professor Ray Lankester, having recently expressed some doubts of the alleged powers of a boy “water-finder.” Dr. McClure, who is chairman of the company by whom the boy is employed, has denied emphatically that the boy, whose name is Rodwell, is an impostor. He says that the lad, when tested, never failed to find either water or mineral veins, the lodes having always been found exactly at the places indicated. The divining-rod which he holds only moves in obedience to the muscular contraction of his hands, and a rod of any kind of wood, or even of any material substance whatever, can be used, provided it be a conductor of electricity. Dr. McClure’s statements have excited considerable comment in England. The phenomena of tests by the divining-rod are not by any means new. They have never been described from a scientific point-of-view, nor has any philosophical explanation of them ever been advanced, but there is no question whatever of their existence, and of their being now regarded by the most advanced scientists as beyond the region of chicanery and imposture. Mr. W. J. Jenks, in a recent lecture on “The Protection of Electric Light Stations from Lightning,” treats the subject very exhaustively, and shows that where the ability to locate electrical or magnetic attraction is vested in an individual the results are absolutely reliable. He instances the case of two gentlemen of Merrimac, Massachusetts, named Prescott, who for several years have given displays of this rare faculty. As an illustration of the certainty with which the Prescott brothers could indicate the location of electrical attraction, Mr. Jenks gives a well-authenticated incident which took place at Amesbury not long ago. Several old citizens were sceptical as to the accuracy of the conclusions supposed to have been reached, and determined on a severe test. Taking twenty or more citizens as witnesses, they requested the Prescott brothers to accompany them, and indicating a stretch of highway before them, some forty or fifty rods in length, stated that some years previous lightning had struck on that road, and wished to be informed as to the exact spot. Proceeding several rods, two cross currents were marked out; both extending for some distance in the travelled pathway and crossed by another at right angles. Testing carefully the roads in both directions, this electrical centre was pointed out as the greatest danger in the vicinity. The party was then invited to examine an ancient volume of official records, where it was chronicled that on the 7th of October, 1802, a man who was driving two yoke of cattle was struck by lightning in that exact spot and, with all his animals, was instantly killed. The occurrence had been deemed at the time so remarkable that the circumstance, with a minute description of the locality, had been recorded, though long forgotten by all but perhaps a few of the oldest citizens.
The Dangers of Electricity.—The rapid spread of electric lighting in America has not been accomplished without very considerable loss of life. From a list compiled by Mr. Harold P. Brown, of New York, we learn that eighty-seven persons have been killed up to the commencement of this year. This is a very serious total, and if there were any likelihood of the rate being maintained, it would supply ample reason for very stringent legislative control being exercised over all electric installations. Happily many of the accidents may be attributed to the want of knowledge which always characterizes a new manufacture, while numbers of them are also due to the hasty and careless methods of erection adopted in America. Both these causes may be expected to decrease rapidly in the future, particularly if the municipalities insist on the mains being placed underground, instead of being strung on poles in the streets. Mr. Brown is well-known from his persistent opposition to the alternate current system; he never misses an opportunity of insisting upon its dangers, and of comparing it, to its detriment, with the direct-current system. Now as the alternate system is rapidly spreading all over London and also in many parts of the kingdom, this is a question which interests us directly. Are we running special risks by permitting its establishment? As far as lighting currents of fifty or one hundred volts are concerned, it certainly matters little or nothing whether they are direct or alternate, for neither will produce any serious injury on the human frame. When it comes to currents of distribution of two thousand volts, then it is quite conceivable that death is more certain by the alternate current, but unfortunately it is also fairly certain with the direct current, so that there is very little to choose between them. A house in which the fittings were charged to such a potential would be as dangerous as a battlefield. What is wanted is sufficiently good workmanship to prevent contact ever being made between the distributing mains and the service wires, and this there should be no difficulty in obtaining. Even if a leak should occur the device of putting the service main to earth at one point will prevent it doing any harm. Mr. Brown refers to two cases in which men were killed by contact with a perfectly insulated wire, their death being caused by the static charge. We feel considerable doubt as to the possibility of any one being killed by a static charge under these circumstances; we prefer to believe that the insulator was bad, probably a mere taping of non-waterproof material. Just as the death-rate on a railway varies inversely as the perfection of the signalling appliances, so the fatalities in America from electricity will decrease as better materials are adopted, and more care is expended in erection.—Engineering.