Nov. 6, 1884] 



NA TURE 



ii 



THE ILLUMINATED FOUNTAINS AT THE 

 HEALTHERIES 



Ni '\Y that the most successful of International Exhi- 

 iis has been closed, we are able to give the 

 final result of the accumulated experience that has been 

 obtained in connection with the working of the illuminated 

 fountains, which excited unqualified admiration. Even 

 on the last night we believe new experiments were tried, 

 and next season these fountains are likely to be finer than 

 ever. 



"I wonder how it is done?" This was one of the 

 remarks most frequently heard in the dense crowd 

 which nightly surrounded the large fountain at the Health 

 Exhibition, watching the many party-coloured jets of 

 water as they rose and fell with an ever-varying combina- 

 tion of brilliant hues. It is believed that an account of 

 the means employed to produce these gorgeous and novel 

 Effects, and of the way in which the water and lights were 

 managed, cannot fail to interest our readers. 



The water-supply is obtained from the West Middlesex 

 Water Company by means of a nine-inch main, which is 

 connected to one of their mains in Kensington Gore. As 

 the water is paid for according to quantity used, it has 

 to be measured, and in order to effect this with as little 

 loss of pressure as possible, the water is passed through 

 three eight-inch Tyler meters, which are to be seen at the 

 north-west corner of the grounds in the vicinity of the 

 fountains. These meters are connected at each end 

 by a four-way junction piece to the nine-inch main, 

 and they were afterwards supplemented by a twelve- 

 inch one on a separate branch. From the four 

 meters the main passes under the water into the central 

 chamber in the basin, and it there branches into three 

 pipes, two of nine inches diameter, and one of six inches. 

 The two nine-inch pipes go round the two sides of the 

 chamber, which is twenty feet square, and are connected 

 together at the opposite side, thus forming a loop round 

 the chamber. Off this main are taken the supplies to 

 the four rings of jets in the basin, and also for the jets on 

 the top of the chamber, each ring having two supplies at 

 opposite sides in order to equalise the pressure. The 

 third branch, which is in direct continuation of the main 

 from the meters, is gradually reduced to three inches, and 

 supplies the centre jet only. 



All the supplies are furnished with screw valves worked 

 by hand wheels. The jets on the top of the chamber 

 consist of the centre jet and four other jets placed at the 

 four corners ; each of these jets is surrounded by a ring 

 of twelve small jets, and there are also four dome and 

 convolvulus jets placed between the corner jets. The 

 supply to the four corner-jets is controlled by a plug- 

 valve, so that they can be rapidly turned on and off. It 

 is by this means that the jumping of the centre-jet is 

 produced, the momentum of the water flowing through 

 these jets being sufficient, on the sudden closing of the 

 valve, to jerk the centre jet thirty feet higher than the 

 point which it reaches from the pressure of the mains 

 alone. 



In order to light up the various jets on the top of the 

 chamber, five circular sheets of glass two feet in diameter 

 are let into the flat roof of the chamber, one under each 

 jet. The pipes leading to these jets go through the roof 

 close to the edge of the glass, and are then bent over it 

 and upwards again, so as to bring the jet itself exactly- 

 over the centre, and it Ls under these panes that the 

 lighting apparatus is placed. This consists of a simple 

 bracket lamp with rack and pinion worked by hand 

 for feeding the carbons, and a third-order holophote lens 

 twenty-two inches in diameter. The carbons are placed 

 at an angle of about 20" with the horizon, and the bottom 

 carbon is the positive one, in order to have the crater 

 turned upwards. The axis of the top carbon is also 

 slightly above that of the lower one, although parallel to 



it. The carbons are eighteen millimetres in diameter, and 

 the current is about sixty amperes. The five lamps are 

 connected in parallel. Each lamp is inclosed in a case 

 to protect the men from the light. Above each holo- 

 phote is placed a frame with five grooves, in which run five 

 frames containing the different coloured glasses by which 

 the various colours are produced. 



When first erected the jets were provided with glass 

 bottoms, and a small lens was placed above the holophote 

 so as to concentrate the centre portion of the ray on the 

 interior of the rising column of water. It was however 

 found that this arrangement considerably reduced the 

 height of the jet, on account of the eddies produced in 

 the chamber at the bottom of the jet, and also diminished 

 the amount of light thrown on the spray, and it was 

 therefore abandoned. 



The principle of interior lighting of a stream of water 

 was applied to three jets from the top of the Corinthian 

 columns erected on each side of the statue of the late 

 Prince Consort, and for this purpose two two-inch pipes 

 were taken up each column, and connected with a cistern 

 from which issue three jets, each illuminated from behind 



by an electric lamp with twelve-millimetre carbons and 

 twenty-ampere current. These lamps are in parallel arc 

 on the same circuit as the large lamps in the centre 

 chamber, suitable resistances being inserted. It was 

 found that the two supplies provided did not allow of a 

 column of water of sufficient diameter being thrown from 

 each jet to prevent its being broken up by the wind, and 

 as it was impossible to increase the supply while the 

 Exhibition was open, these effects were rarely used. The 

 current for these eleven lamps, amounting to 420 amperes, 

 is generated by a compound shunt-wound Simens B 2 

 machine placed in the electric light shed. The armature 

 of this machine is built up of copper strips with spaces 

 between, and is thus especially adapted for the work it 

 has to do, which at times is very severe, as, the lamps 

 being hand-fed, the arc is not struck as rapidly as in an 

 automatic lamp, and the machine is therefore short- 

 circuited for an appreciable space of time on starting or 

 relighting any lamp. The electromotive force at the 

 machine is eighty-four volts. From the machine the 

 current is conveyed to the small hut near the meters by 

 two well-insulated cables of nineteen strands of No. 12 

 copper wire, and from the hut it is distributed to the 

 island lamps by an insulated cable of nineteen No. 10 wires 



