Jan. 13, 1887] 



NATURE 



261 



burning at the mouth of the jav is the effect of the great affinity 

 which exists between the atoms of hydrogen and the atoms of 

 oxygen which, in the atmosphere of the room, borders upon the 

 hydrogen of the jar. Further up in the jar the hydrogen atoms 

 have no oxygen atoms wherewith to combine. Now, it may 

 seem a surprising assertion to make, but it is nevertheless true 

 that one could place a red-hot jioker in the body of gas in a 

 balloon without setting fire to it. If I were to ask anyone 

 here so to do, I am sure he would decline, and say the gas woiild 

 catch fire as he placed the poker in the mouth. That is quite 

 true ; and, to perform the experiment successfully, he would 

 have to avoid the borderland altogether. Here is a puzzle 

 to put to your friends : — How to put a red-hot poker into 

 the body of a gas-balloon without setting fire to the gas. 

 Njw, I will show you how to do this. [Experiment shown.] 

 Here is a glass globe, through which a continuous stream of 

 coal-gas is passing. You see this must be so, for I have ignited 

 the gas jet at the top of the globe. Now I have stretched a 

 little piece of platinum wire across the terminals of an electric 

 battery, and placed these terminals inside the globe. Now I 

 will cause the electric current to pass through the piece of wire, 

 and it becomes white-hot, and we have this condition of things : 

 a piece of white-hot metal unprotected inside a globe filled with 

 gas. Now, if we were to substitute a balloon for the globe, 

 and have a battery of exceeding power, and if we were to place 

 a poker between the terminals of the battery, the red-hot poker 

 in a balloon would be 2. fait accompli. The incandescent lamps 

 which we place inside the balloon consist of a thin filament of 

 carbon inclosed in a glass globe exhausted to a high degree of 

 air. This filament of carbon is raised to a white heat by the 

 electric current. [Experiment shown.] I have thrown the 

 image of a filament of carbon upon the screen, rendered thus 

 incandescent. On my table I h.-ive another globe filled with gas 

 inside, which is our incandescent lamp. This is the condition 

 of things we have in the balloon. [Experiment shown.] Now, 

 some person may say : " Suppose by accident you get an explosive 

 mixture of oxygen and hydrogen inside the balloon, and that 

 tliis fragile little bulb breaks." Well, if it does break, one lamp 

 will be lost ; that will be all the damage done, for the oxygen 

 present will at once destroy the carbon filament. [Experiment 

 shown.] I will show you this experiment by breaking an in- 

 candescent lamp in the midst of this inflammable piece of tow ; 

 you see, as I break the lamp, the light instantaneously goes out, 

 as the action of the oxy.;en is to destroy that delicate carbon 

 bridge which you have seen depicted on the screen. Now, one 

 more of this series of experiments. [Experiment shown.] Here 

 is another globe filled with gas ; in this I discharge a naked 

 electric spark between two platinum points. I perform this 

 experiment to show you that, even if there were a bad connec- 

 tion in the electric arrangements inside the balloon, there would 

 be no danger of firing the gas. However, in the special form I 

 provide, I obviate all chance of any sparking, so that, in case of 

 the contingency of there being an explosive mixture of oxygen 

 and hydrogen inside the balloon, there would be nothing to deter- 

 mine it. That an electric spark can fire a mixture of hydrogen 

 and oxygen in certain proportions I can show you by producing 

 this respectable electric spark by means of this induction- 

 machine, and then bringing near it a jet of coal-gas. [Experi- 

 ment shown.] 



A convenient size for one of these signalling-balloons is a gas 

 capacity of some 4000 cubic feet, or, if required, they can be 

 made smaller than this. Varnished cambric is a suitable mate- 

 rial. I have two separate arrangements for suspending the 

 lamps inside the balloon ; the first consists of a holder made 

 like a ladder, the lamps being placed one above the other in 

 multiple arc. Here is this arrangement before you, with the 

 lamps lit up. This arrangement is convenient because of the 

 small breadth of the ladder, which is easily admitted into the 

 neck of the balloon. The ladder arrangement casts a small 

 shadosv on the balloon. In my opinion this shadow is of no 

 consequence whatever ; but I have an alternative method which 

 obviates the appearance of any shadow altogether. It consists 

 of a ball, from which project lamps at various angles ; the 

 arrangement is protected from risk of breakage by a wire frame- 

 work. [Experiment shown.] 



The form of contact-breaker which produces the intermittent 

 ll.ishes of light is in form somewhat like a Morse key. In reality 

 it is essentially different. An ordinary Morse key, such as is 

 used in telegraphy, would not withstand the large currents used 

 to light the lamps. In my latest form of contact-breaker I use 



carbon-contacts. These can be easily renewed at trifling cost 

 when worn away. [Experiment shown.] I have also on my 

 lecture-table another form of contact-breaker [experiment 

 shown], in which there is a rubbing contact faced with platinum. 

 The leads which convey the electric current to light the lamps 

 must be as light as possible, consistent with the current they 

 have to carry, and [experiment shown] here is a special type of 

 cable I have had manufactured for the purpose. By means 

 of the model balloon before you, I will now show you the 

 action of the key. We will flash the words " A Merry Christ- 

 mas and Happy New Year to you all." [Experiment shown.] 

 On the switch-board which contains the key I have an 

 arrangement to switch on the lights in the balloon continuously, 

 in this manner, because these portable balloons thus illuminated 

 would be useful for other purposes than for flashing signals, viz. 

 for a preconcerted signal, or as a "point-light" lo guide 

 advances or retreat. 



The source of electrical power for working the lamps inside 

 the balloon may be varied according to circumstances. It may 

 be: (I) a small dynamo; (2) a storage battery; (3) a primary 

 battery. Each of these three forms of power can be supplied in 

 portable and convenient form. In some cases, where there is a 

 stationary dynamo-machine in close proximity, storage-cells may 

 be conveniently used, as they can be charged from this stationary 

 dynamo, and brought into the field as required. I used storage- 

 cells just now to light up that ladder of lamps and for working 

 the lights in my model balloon. These storage-cells are, you 

 see, arranged at the foot of my lecture-table. A portable way of 

 obtaining power would be, I think, to use a little gas-engine 

 with dynamo combined, such as, by the courtesy of Messrs. 

 Crossley Brothers, I am enabled to show you this afternoon at 

 work. [Experiment shown.] This might be fixed on the 

 waggon, with all the other apparatus connected with the bal- 

 loon? The engme would be worked by the gas, which is always 

 a necessary adjunct to the balloon. The gas-supply might be a 

 portable apparatus for generating the gas, or else the method of 

 storing gas in steel bottles could be adopted. This has been done 

 successfully by our own Government. At the Inventions Exhi- 

 bition a bottle of compressed gas was exhibited in the War 

 Department. I now wish to show you how easily gas may be com- 

 pressed, stored up, and used when wanted. Here is a small 

 bottle of compressed hydrogen, and I will soon transfer the gas 

 from that to this goldbeater-skin balloon, which now rises to the 

 ceiling. [Experiment shown.] There is another method of 

 lighting these balloons — by using a primary battery. There is 

 a very excellent primary battery now in the market, invented by 

 M. Schanschieff. A good primary battery has long been a great 

 desideratum. For some time I have searched to find one that 

 was anything near the mark for electric lighting purposes. This 

 battery which is before you is the best I have had in my hands, and 

 I am applying it to several of my patent arrangements. I am glad 

 to be able to show you one of these batteries in working order. 

 [Experiment shown,] In this comparatively small compass we 

 h.ive 32 cells. The size of each cell is 3^ inches by 2 inches. 

 In the cells we have a sin^^le fluid solution — sulphate of mercury 

 acidulated. There is a sample of the sulphur in this bottle. Now, 

 with most single-fluid batteries we have what is technically 

 called polarisation, which means diminution of electric power. 

 Mr. Schanschieff" has overcome this polarisation, and in over- 

 coming it he has done a great deal towards the development of 

 electrical appliances. There is one piece of apparatus connected 

 with the balloon worth mentioning. This is the reel for windii^ 

 the cable. [Experiment shown.] The electric connection is 

 made, you see, as the cable unwinds. 



The advantages which I claim for this method of signalling 

 are, briefly : It facilitates night-signalling ; it facilitates signalling 

 to long distances ; and in places where the ordinary methods 

 would fail to be of any use, such places as hilly and wooded 

 districts, the apparatus is portable and simple ; the balloon 

 shows a large body of light. In order that you may realise the 

 use of a balloon in time of w.ar in a place where ordinary sig- 

 nalling would be of no use whatever, I have prepared the illus- 

 trations which my assistants will now throw upon the screen. 

 Here we have a mountainous region. There are supposed to 

 be two friendly armies separated by chains of mountains, and 

 wishing to communicate. Now these two armies might be pos- 

 sessed of every other modern appliance for signalling from the 

 ground without being able to make a signal seen by either side. 

 Therefore, in the scene before you, the signallers of one army 

 are depicted as filling the portable signalling-balloon with gas 



