1U2 



♦ KNOV/LEDGK 



[Feb. 6, 1885. 



n-ould quite certainly, tbat whatever pains his uller ego 

 luight liave to suti'er, not the slightest rtcollection of them 

 would remain in Lis ordinary condition % 



There is indeed almost as strange a mystery in uncon- 

 sciousness as there is in the phenomena of dual conscious- 

 ness. The man who has passed for a time into un- 

 conciousness through a blow, or fall, or fit, cannot help 

 asking himself, like Bernard Langton, in that weird tale, 

 '■ Elsie Venner," "Where was the mind, the soul, the 

 thinking principle all that time \ " It is irresistibly 

 borne in upon liim that he has been dead for a time. As 

 Holmes reasons, " a man is stunned by a blow and becomes 

 unconscious, another gets a harder blow and it kills him. 

 Does he become unconscious, too 1 If so, irhen, and Jlo^v does 

 he come to his consciousness? The man who has had a slight 

 ar.d moderate blow comes to himself when the immediate 

 shock passes off and the organs begin to work again, or 

 when a bit of the skull is 'pried ' up, if that happens to be 

 broken. Suppose the blow is hard enough to spoil the 

 brain and stop the play of the organs, what happens then?" 

 So far as physical science is concerned, there is no answer to 

 this question ; but physical science does not as yet compre- 

 hend all the knowable, and the knowable comprehends not 

 all that has been, is, and will be. What we know and can 

 know is nothing, the unknown and the unknowable are alike 

 infinite. 



THE YOUNG ELECTRICIAN. 



By W. Slingo. 



(Continued from page G4.) 



THE many demands made upon our space a fortnight 

 since compelled me to curtail my article, and so to 

 leave unsaid a few remarks on solder and soldering, which 

 I will now proceed to rijake. 



Ex. XII. The process of tinning the soldering-iron 

 may be facilitated by employing a tinuiug-tray, consisting 

 of a spoon or tray-shaped piece of slieet-brass, iron, or 

 other convenient metal. The tray may be made by cutting 

 from each of the corners of a piece of metal (about '2 in. 

 square) little pieces, say, a quarter of an inch square, and 

 then bending up a quarter of an inch of the sides; this will 

 make a tray 1^ in. square. In this is a small quantity of 

 solder and a little spirits of salts. The liot iron, if properly 

 cleaned — by filing with a bastard (coarse) file — will 

 become tinned immediately on heating it into the solder. 

 The success of soldering depends to a great extent upon a 

 due observance of the following pi-ecautions, (n) keep the 

 iron in a clean tinned state ; (6) never allow the iron to 

 become redhot, or the tin will be burnt off (necessifatin" a 

 repetition of the filing and tinning process), but heat it 

 just sufficient to melt the solder, and wipe the end with a 

 c?e((7i rag ; this leaves the iron with a good tinned surface ; 

 (c) thoroughly cleanse the surfaces of joints to be soldered, 

 ('0 '^PP'y carefully the spirits or resin, whichever is usfd. 



Ex. XIII. It was said (Ex. XI.) that strip solder should 

 be used. Ordinarily, when strip solder is specified, a soft 

 solder is meant. Some comparatively hard solders are 

 made in the strip form — that is to say, the solder is run into 

 strips a foot or so long, a quarter of an inch wide, and 

 about a sixteenth thick. Ordinary soft solder, although 

 easy to work, in too soft and too easily broken, if used where 

 any strain is exerted. Consequently, in forming a metallic 

 junction between pieces of copper or brass, " blowpipe " 

 solder answers best because of ita comparative hardness. 

 Having learned to work soft solder, the young worker 

 should next try his hand with the more difficult blowpipe 



sc.lder. It may be obtained at the rate of one shilling a 

 pound, or a single strip may be purchased for a penny. 



E.v. XIV. The soldering-iron is a most important tool, 

 and no worker should be without one. I give here the 

 details for making one, at the cost of a few pence. A 

 piece of bar copper, A B, Fig. 1, about 3i in. long and | in. 



square, is brought to a square point at the end A, the 

 facets making an angle of about GO" with each other. The 

 end B has a saw- or file-cut, g in. wide and h in. deep. A 

 piece of round iron rod (BC), 5-16 in. in diameter and 

 about 4 in. long, is flattened out by making the end B red- 

 hot, and then spreading it with a hammer, upon an anvil 

 or iron block, to a wedge shape. The end C is reduced to 

 a slightly tapering square. The iron, having been flattened 

 to the necessary extent, is then fixed into the sawcut in 

 A B. A small hole is then drilled * through the copper- 

 prongs made by the saw- or file-cnt, and the iron 

 tongue, and a rivet of any convenient metal passed 

 through and hammered down, as illustrated in the 

 figure. The copper and the iron will then be 

 rigidly attached one to the other. A wooden handle 

 having been procured (a chisel or file handle will do, or 

 a new one may be obtained for a penny or so), the end 

 of the iron is made red hot and is then burnt for half an 

 inch or so into the handle, and then removed and allowed 

 to cool. When cool, place the iron stem in a vice,t or any 

 other convenient place, and drive the handle on to the 

 iron for an extra quarter of an inch. This must be done 

 carefully, or the handle may be split. When finished, a 

 a soldering-iron will have been nrade at the most trifling- 

 cost, and yet it will prove quite as efficieiat as any that may 

 be purchased, and will be found quite large enough for any 

 purpose for which we may require it in the course of these 

 [lapers. 



Ex. XV. For the purpose of cutting wire, &c., pliers 

 will be found essential. The worker had better, therefor-e, 

 be provided with a pair of 4-inch cutting-pliers and a pair 

 of 1-inch nipping-pliers. 



Ex. XVI. For cutting metal-foil or very thin sheets, a 

 good pair of scissors will suffice. 



Ex. XVII. Stouter sheets, if not too thick, yield to a 

 pair of shears with 3-in. blades and a 7-in. handle. In 

 using them the metal to be cut should always be placed as 

 near as possible to the rivet which holds the blades together. 

 The metal may then be cut for an inch or so, and then 



advanced again towards the shears. A little practice will 

 make evident the necessity for not allowing the blades to 

 cut through their whole length, otherwise a series of 

 ridges or notches will be left. One other precaution must 

 be observed, and that is to keep the cutting edges in as 

 nearly the same plane as possible, that is to say, press the 

 handles apart and so press the blades together. 



Ex. XVIII. Even shears will not do when we wish to cut 



* Drills and drilling will be dealt with in the next succeeding 

 article. 



t See next article. 



