494 



♦ KNOWLEDGE ♦ 



[June 12, 1885. 



and Amelia Osbornes — apart, that is from subordinate 

 characters.* 



It is noteworthy that women bold this opinion ; indeed, 

 I am not sure that they are not chiefly responsible for the 

 opinion that all Thackeray's amiable women are fools and 

 all his clever women rogues. Yet no opinion could be 

 much further from the truth. Theo and Hetty Lambert 

 suffice as illustrations of Thackeray's power in delineating 

 amiable women who are not fools and clever women who 

 are not only not rogues, but of sweet and attractive 

 dispositions, t 



In Ethel Newcome we have the two qualities combined 

 in still more marked degree. Surely, by the way, there is 

 no more charming picture than that of Ethel Newcome, 

 infinitely more attractive, with all her faults, than she 

 would been without them, and without her noble and 

 touching repentance. 



(To he contimted.) 



THE YOUNG ELECTRICIAN. 



By W. Slingo. 



{Continued from p. 455.) 



HAVING, as I said a fortnight since, dealt with such 

 tools and appliances as the tyro in experimental 

 electricity is likely to require, I would now direct his atten- 

 tion to the experiments themselves. 



One little word may here be uttered, and that is to 

 repeat the old warning, that to succeed in any experimental 

 science frequent practice and exercise are necessary. The 

 reader may rest assured that no experiment will be detailed 

 which cannot be repeated by anyone of ordinary skill and 

 intelligence. Let it ever be remembered, however, that 

 experimenting is an art which is not inborn, but which 

 must be acquired. 



Some of our readers would doubtless be best satisfied 

 were I to at once enter into details concerning the construc- 

 tion of elaborate pieces of apparatus ; but I am anxious not 

 only to impart to this series of articles an air of complete- 

 ne&s, but also to atford our younger constituents an 

 opportunity of gaining an insight into the rudiments of 

 experimental practice. Let us, then, in the first place, 

 consider the 



PRODUCTION OP ELECTRICITY BY FRICTION. 

 Pr. 1. When two bodies are rubbed one over the other, 

 each body becomes electrified. As, however, electricity is 

 only a "force" or condition into which "matter" is 



* The only opinion I have heard of, which, in my judgment, 

 compares with this in absurdity, is Thackeray's own opinion (ex- 

 pressed in one of his Brown letters) that all Shakeapeare's heroines 

 are alike. Macaulay, by the way, was of the same opinion, though 

 I cannot at the moment recall any passage in his writings where 

 he has said as much ; but Mrs. Harriet Beecher Stowe mentions in 

 her " Sunny Memories" that Macaulay expressed that opinion to 

 her in conversation. She adds, if I remember rightly, that no 

 woman would agree with him in that opinion, and I should imagine 

 very few men would either, even though the opinion were modified 

 into the view that Shakespeare's sprightlier heroines were all alike, 

 and his gentler heroines also. 



t Let not a hasty reader of the " Virginians " point oat here 

 that Jack Lambert says of Hetty that she is sometimes " harsh," 

 for there cannot be a shadow of doubt that what Thackeray wrote, 

 or at any rate intended to write, was " arch," as the context most 

 plainly shows. By the way, he was a rather careless reader of 

 proofs, for not very far from the passage in which this mistake 

 occurs is another where the word " general " has been altered into 

 " quarrel," aad so stands in all the editions I have yet seen. " Did 

 the General ever make you Jealous ? " George Warrington rather 

 rudely asks of Mrs. General Lambert; but this has been altered 

 into the absurd question, " Did the quarrel ever make you 

 jealous ? " 



thrown, it is invisible, and its presence can only be detected 

 by ita results. Now the result of imparting electricity to, 

 or of electrifying, a body, is to endow it with an attractive 

 power over other bodies. 



It will often be noticed that the greater the 2}hi/sical 

 difference between the two bodies rubbed together, the 

 greater will be the degree of electrification. 



It will not always be easy to detect the presence of 

 electricity in both bodies, so we will first perform a few 

 experiments, with a view to obtaining a charge upon one 

 of the bodies, ignoring the other. 



In order to .show the attractive power possessed by an 

 electrified body, we require a few simple pieces of 

 apparatus. 



E.\. LXVII. — The first is a suspending support, such as 

 that illustrated in Fig. 36, which consists of a wooden base, 

 A B, 3 in. or 4 in. sq., and a piece of brass or copper wire, 

 C D E, one-eighth to three-sixteenths of an inch in diameter, 

 and about 2 ft. long bent approximately, to the shape 

 shown, the end being fixed in a hole in A B, made 

 with a bradawl or gimlet, and the end E being bent 

 upwards to receive a piece of cotton, silk, &c. 

 D 



Fig. .30. 



Ex. LXVIII. — Procure from a seller of watchmaker's 

 sundries or elsewhere a few sticks of elder pith, and cut 

 one or two of them into balls with a sharp penknife. 

 When it is required to suspend these balls, run them 

 through with a needle supplied with cotton or silk, accord- 

 ing to requirements, securing the thread by making a neat 

 knot. Cut off the thread as close to the knot as jiossible, 

 leaving a foot or so of thread on the other side of the ball 

 for suspending, as in Fig. 36. 



Ex. LXIX. — Get, for a few pence, a book of Dutch 

 metal at a picture-frame maker's, or elsewhere; abstract, by 

 means of a clean knife, one of the sheets of metal, and 

 place it between two pieces of note-paper ; lay these on a 

 piece of board, and with a sharp pen-knife cut into as 

 many small pieces as possible. The use of the note-paper 

 reduces considerably the risk of tearing the metal leaf 



Ex. LXX. — Pass a vulcanite comb through the hair (if 

 dry) a few times, and then present or place it near to a 

 small tuft of feathers, or a pith ball suspended by a piece 

 of cotton or silk thread (Fig. 36). The feather or pith 

 ball will be attracted by or drawn towards the comb, a 

 phenomenon which did not ensue on presenting the comb 

 prior to its being passed through the haii-. 



Ex. LXXI. — Rub a stick of warm sealing-wax, shellac, 

 sulphur, or a wooden road coated with two or three layers 

 of shellac varnish (Ex. I.), with a piece of hot flannel, or 

 fur, or even on a dry coat-sleeve, and present it to the 

 feather or pith-ball ; attraction ensues, and the ball is drawn 

 into the position F' Fig. 36. 



