496 



♦ KNOWLEDGE ♦ 



[June 12, 1885. 



facturo is concerned. The smooth iiush end first made may 

 be painted in radial sections, or in any other way the young 

 electrician may prefer. 



Such a drum laid on a smooth level table may be made 

 to roll along it with a comparatively feeble charge of 

 electricity. Why this is, we can ascertain presently. 



(To he coiitimied.) 



TO STRENGTHEN THE ARMS. 



By Eichakd A. Peoctor. 



I SET to work a few days since collecting together for 

 publication, in book form, my papers on " How to Get 

 Strong," which I supposed I had completed ; but I found to 

 my horror a rather serious omission. I had not written a 

 word about the arms, except (which probably led to my forget- 

 fulness in the matter) in giving many exercises for the arms 

 where I was dealing directly with the chest, waist, loins, 

 and legs. The arms, from the shoulders to the finger-tips, 

 require to be dealt with separately; and I proceed to correct 

 the omission, premising that the series of papers will 

 shortly be published in collected form, in company with the 

 papers on corpulence, corset compression, rowing, swim- 

 ming, and exercise for middle and advanced life. 



I may mention, in passing, that a railway accident in the 

 summer of 1SS3 led in my own case to the interruption, 

 for several mouths, of those exercises which I advocate as 

 desirable to maintain the body in a healthy and active con- 

 dition. All exercise was rendered painful by the jarring 

 effects of that accident, especially in the region of the 

 upper spine, and the base of the brain. It is only recently 

 that I have felt " myself again " in this respect ; and I 

 can answer for it, from experience, that the interruption of 

 systematic daily exercises, such as I have described in these 

 columns, affects seriously, while it lasts, the capacity for 

 other kinds of work. 



It is commonly supposed that the exercises of which 

 most Englishmen are fond, and especially rowing, develop 

 the muscles of the arms and shoulders in greater degree 

 than they develop the muscles of the body. This, how- 

 ever, is a mistake. As a rule, Englishmen are better in 

 loins and legs than in shoulders and arms. Rowinw in 

 particular affords very insufficient exercise for the arms. 

 Of course, many rowing men assert that rowing exercises 

 every muscle of the body, an assertion which needs no con- 

 tradiction, for, as Mr. Maclaren well says, no exercise gives 

 more than employment for a portion of the body. Rowing 

 in heavy boats gives exercise to the shoulders and arms, no 

 doubt ; but even in these the work falls more on the back, 

 loins, and legs than on the arms, while in the lighter kinds 

 of boats, and especially in racing boats, the forearm and 

 upper triceps alone get any work worth considering, the 

 biceps and the rest of the upper arm getting scarcely any 

 work at all. The biceps will gain more from a week's 

 steady work with the dumb-bells and the clubs than from 

 a year of rowing ; nay, so far as the shapeliness of the arm 

 is concerned, rowing positively injures the biceps, by 

 making it look relatively smaller than it had been before. 

 Cricket and lawn-tennis give more exercise to the arms ; 

 but if too exclusively used, they destroy all symmetry. 

 I never yet saw a cricketer of the very enthusiastic sort 

 with well-shaped arms. 



Let us now consider the arm in detail, from the shoulder 

 to the hand. 



THE SHOULDERS AND UPPER ARM. 



For strengthening the shoulder muscles exercise with 

 the clubs is invaluable. So are some of the pulling exer- 

 cises already considered. But no apparatus of any sort is 

 really necessary. 



Standing upright, the arms hanging down, carry the 

 arms from the sides forwards and upwards and then back- 

 wards as they pass down to a horizontal position, turning 

 the palms of the hands upwards. Continuing the motion, 

 let the arms be lowered to the sides till the hands strike 

 the backs of the thighs. Repeat the process twenty or 

 thirty times. You will soon feel that the muscles around 

 the shoulder are doing good work and getting well limbered 

 up. With dumb-bells the work is heavier, but if the dumb- 

 bells are too heavy, the work is less effective in making the 

 shoulder muscles quick and active. With clubs the centri- 

 fugal tendency is somewhat too marked, until the shoulder 

 muscles have been strengthened by exercise without them ; 

 but later, this exercise with the clubs will be found excel- 

 lent, and the slow lowering of the clubs from the horizontal 

 position on each side, and rather backward, is particularly 

 beneficial. In fact, in nearly all exercises with the clubs, 

 slow movements of lowering and raising, while the clubs 

 are held far out, are capital for strengthening and steadying 

 the muscles of the upper arms and shoulders. 



Next, standing upright, with the arms raised vertically, 

 lower them steadily forwards till they are at the sides, 

 forcibly continuing the motion till they have been carried 

 as far back as they will go, keeping the body upright. 

 Repeat this a score or so of times, each time holding the 

 arms as far back as they can be carried, while you count 

 ten slowly. You will find the muscles of the upper back 

 near the shoulder considerably exercised even without 

 lifting dumb-bells backwards in this way. But as you get 

 accustomed to the work and tt grows lighter, use dumb- 

 bells, or any other convenient weights. To limber up the 

 same muscles carry light clubs from over the head forwards 

 downwards and so backwards, as far as they will go, 

 keeping the body all the time rigidly upright. 



(To be continued.) 



THE PHILOSOPHY OF CLOTHING. 



By W. Mattieu Williams. 



X.— GASEOUS CLOTHING MATERIAL (continued). 



N my last I stated some examples of that adhesion of 

 gaseous matter to solids which, as Rumford has 

 shown, contributes such important aid to the etficacy of 

 clothing. The subsequent progress of science has not 

 only coufii-med his conclusions, but has presented this 

 agency as a still more potent factor than it appeared to 

 be in his day, when the general subject of gaseous adhesion 

 had received so little attention. 



We now know that not only do gases remain obsti- 

 nately adherent to solid surfaces, but that they are con- 

 densed thereon so powerfully as to become, in some cases, 

 apparently liquefied and even solidified. 



In the experiment with the blackened card described in 

 my last, the solid which effected the atmospheric adhesion 

 was carbon. The film of carbon and the film of adherinc; air 

 m this case are both so small and light that the quantity of 

 adhering gas is not practically weighable or measurable. 

 By using carbon in larger quantity and of suitable form the 

 amount of gas adhering to its surface may be easily 

 measured. Charcoal is carbon in such a form, its porous 

 structure providing a great extent of surface packed in 



