86 



♦ KNO\VLEDGE • 



[Aug. 1, 1884. 



A detailed statement of the cost of maintaining 

 the Westinghouse brake on 2,666 vehicles for 

 two years is given, and this is particularly in- 

 structive. From it we find that, including the 

 cost of replacing the whole of this stock with new 

 hose pipes, for reasons explained in the report, the total 

 expenditure for maintaining both the brake proper and the 

 brake rigging, exclusive of brake blocks, is under Os. Gd. 

 per vehicle per annum. As Mr. Harrison points out, 

 however, the cost for hose pipes should be reduced by 

 one-half to get an average, which brings the sum to only 

 7s. per vehicle. This '• amount includes everything but 

 brake blocks, which are common to all brakes, and is made 

 up as follows : — Maintaining and repairing parts of brake 

 and rigging, 8d. per vehicle per annum ; hose renewals, 

 2s. 4d. per vehicle per annum ; men's wages, testing and 

 overhauling, and inspectors' salaries, 4s. ; total, 7s. This 

 sum is equal to about 1 j per cent, for the first cost of the 

 brake proper and the brake rigging — a truly surprising 

 result, which, as the report says, "shows conclusively that 

 there is great economy in the maintenance of the 

 Westinghouse brake." 



Surely this, from so great an authority, should suffice to 

 convince any one ; but the question,fviewed from a public 

 standpoint is not, except to a veiy small extent, one of ex- 

 pense. If railway directors are determined to remain 

 admirers of such appliances as the vacuum non-automatic 

 brake because of their " simplicity and beauty," they must 

 be convinced of the paramount necessity of ensuring, as far 

 as possible, the safety of their customers. There is a 

 Board of Trade requirement concerning brakes which, 

 however, is not followed out, and signs are not wanting of 

 an urgent appeal being made to Parliament to enforce com- 

 pliance ; but I take it that travellers have the question, to 

 a great extent, in their own hands, and can call for reform 

 with a voice more potent even than that of Parliament, by 

 taking such alternative routes to their various destinations 

 as will enable them to repose confidence in the appliances 

 introduced for their security. 



Speaking of the efficiency of the Westinghouse brake, 

 Mr. Harrison, in the report above referred to, points out 

 that the great object of the introduction of continuous 

 brakes was not for the mere stopping of trains at stations, 

 but that it might be used as an emergency brake to pre- 

 vent accidents, and every day's experience shows more 

 clearly the efficiency of this brake for this purpose and in 

 diminishing the extent of damage when accidents do occur, 

 and it is generally liked by all engine drivers who have 

 used it. It has been found especially useful for working 

 steep inclines, of which there are many on the North- 

 Eastern system, in some the gradients being as steep as 

 1 in 37. 



THE INTERNATIONAL HEALTH 

 EXHIBITION. 



X.— WATER AXD WATER-SUPPLIES— (con/i7itted). 



II. Artificial Waters necessarily include samples of 

 the most varied characters. For the sake of convenience, 

 we shall here group together those which are purposely 

 prepared by man to meet certain ends, and others which 

 result indirectly through the agency of living beings. To 

 the former class distilled and aerated waters belong, to the 

 latter, plant-waters and sewage. 



1. Distilled Water may be prepared from any of the 

 numerous varieties which we have already considered. 

 The process is conducted in an apparatus called a still 



which consists of a suitable boiler of metal, glsiss, or stone- 

 ware, to the summit of which a pipe is fixed for the pur- 

 pose of conveying away the steam or vapour produced by 

 the boiling of the water into a condenser. The form of 

 condenser usually adopted is a coiled tube immersed In a 

 vessel of water, which is kept cold Vjy a continuous current 

 from a cistern. The steam on passing through the condenser 

 becomes reconverted into watei-, and the liquid so produced 

 is practically pure water, freed from most of its gaseous, 

 and all its solid, impurities. 



The "foreshot" of the distillate should be rejected, as it 

 is liable to contain gases, organic matters, acids, and am- 

 monia, which obtain in the original water. In like manner, 

 the process should be discontinued before the still has been 

 exhausted, in order to reduce the possibility of a passage 

 over of residual products. Distilled water thus ])repared 

 is particularly greedy of dissolvable substances, and will 

 even attack matters which natural waters would leave un- 

 afliected. Its preparation in vessels with pipes of metal, 

 more especially of lead, and its storage in leaden receptacles, 

 should be avoided, to prevent a chance of poisonous con- 

 tamination. We would, therefore, once more direct the 

 attention of our readers to Jlessrs. Doulton & Co.'s exhibit, 

 where they may view with satisfaction the admirable 

 utilisation of stoneware for chemical apparatus. 



2. Aerated Waters are only manufactured for beverages ; 

 they do not come within the scope of our present 

 inquiry ; but, as we have already dealt with some of the 

 more important aspects of this question, we would now re- 

 direct our readers to what we have stated with regard to 

 the preparation of such drinks from a sanitary point of 

 view, and to Messrs. Barnett dc Foster's stand in the 

 Western Gallery of the Exhibition. 



3. Plant Waters. — In tropical forests, many plants have 

 the power of collecting and storing water in their tissues, 

 which is often a boon to the parched explorer. The well- 

 known Traveller's Tree aflbrds copious draughts of cool fresh 

 water on being pierced.* The grateful juice of the Cocoa- 

 nut palm fruit affords a beverage which in quantity is 

 sufficient to allay thirst, and, in palatable quality, excels 

 the most delicious of artificial drinks. The cut inflor- 

 escences, in their estivation, of both the Cocoanut and the 

 graceful Palmira, yield a delightfully refreshing nectar, 

 which, however, is prone to ferment very speedily, and is 

 then commonly called " toddy " by the natives of India. 

 All these waters are of the nature of elaborated saps, but 

 yet from their abundance in regions where water is scarce 

 or polluted, are of sufficient importance to demand some 

 attention here. Other plants with succulent stems, leaves, 

 fruits, itc, are not to be classed with the above, since they 

 are incapable of satisfying thirst, and moreover, their very 

 existence presupposes an ample supply of wholesome water. 



4. Seioage may be defined as the concentrated refuse of 

 communities of human beings. In towns such as Man- 

 chester, where excrementitious waste products are utilised, 

 and are not permitted to enter the drains, sewage is com- 

 paratively harmless ; but in districts like London, in spite 

 of every cave, the pollution of rivers from such sources 

 often assumes a most dangerous aspect. Royal Commissions, 

 Metropolitan Boards, and Houses of Parliament all seem to 

 be ineffectual to cope with impending evils ; the first points 



* The munificent gift of Miss North to Kew Gardens contains a 

 series of beautiful paintings of tropical plants. Amongst the most 

 noteworthy is the "Traveller's Tree (Ravenala Madagascariensi$), a, 

 striking example of the Banana tribe (Musacece). It may here be 

 observed that the large expanded leaves, with their grooved mid- 

 ribs, afford channels for conveying the rain-water to sheathed 

 recesses at their bases. The water thus collected remains fresh 

 and limpid, and may be obtained by piercing through the attached 

 ends of the soft, loosely-textured petioles. 



