April 27, 1883.] 



♦ KNOWLEDGE ♦ 



255 



another, the lenses most do harm, if of eqnal power, instead of 

 good. Myopia. 



[I am particularly interested myself in this qoestion, seeing; that 

 my left eye is very short-sitrhted (I should use power " 12" if I 

 used any glass at all), while my right eye shows distant objects 

 with perfect distinctness. With adapted spectacles 1 seo double. 

 Bat as I get alou°; very well without glasses, this does not trouble 

 me.-H. P.] 



LETTERS BECEITED. 



A. T. Hartkt. I fancy a State Minister of Science would find 

 all his time taken up in distinc^uishinpf lionost workers from mere 

 money seekers. — W. W. Bishops. In Kxowledoe for May 4. — J. 

 U. Thomson. Many thanks ; but the scales would be too perplexing,' 

 to most readers.— N. K. PrNSHOx. If you try to give definite 

 shape to the rim; you suggest round Mira, ^-ou will find that the 

 variations of the star cannot possibly be accounted for in measure 

 and degree by that theory. — D. Kobertson', Ioxe. Not yet written. 

 — F. A. LrrroN. Answered elsewhere. Ur. U. Draper published 

 no such work. — S. Dobson notes that colour-bliudness is less 

 common among women than among men. — J. T. Pope. Squaring 

 the circle not to be effected in that wav. — S. Skinxek, H. II. 

 Ellis., J. C, \. U. A., Erx. J. R. Thanks.— "W. Miller, H. 

 K. MuiBUEAD. The difference between stored energy and the actual 

 use of such energy is surely too obvious to need pointing out. — H. 

 Stock. There i* that trouble about bulk. A balloon to raise even 

 the human body alone must be at least 1,000 times as bulky ; to 

 raise a car-load of travellers an inconveniently large balloon 

 would bo wanted, and the wind would play unpleasantly 

 ■with such a bulky monster. — F. H. E. (1) A comet's opposition 

 ia not necessarily its ai>helion ; (2) the inclination of its orbit 

 may exceed or fall short of its greatest latitude, if this is what you 

 mean by its greatest inclination. (3) The " Vade Mecum do 

 I'Astronomie " is not known to mo; if it suits "every one not born 

 with a telescope in his mouth," it must be widely useful. I know 

 of no "work in English that does." — R. R. Baines. Many thanks, 

 but information crowded out. — E. A.nderson'. If a Southerner can 

 be called a "Yankee," your kind wnsh is already fulfilled. Your 

 triangle puzzle is perfectly dreadful. I agree with yon (but that 

 counts for nothing). The other bosh about the constitution is, I 

 fear, propounded very much as yon put it. My old theory (for 

 particulars inquire at Century Club, New York) comes in well 

 here. There 's a deal of nonsense about. — Hallyards. Fear the 

 derivations rather too recondite. — Original Subscriber. More find 

 difficulty in adding numbers including both odd and even, than in 

 adding all odd or all even numbers. — G. G. S. There is now no 

 correct way of pronouncing Latin. You may say lioostiecoos or 

 Busty Cuss, Viesissim or We kiss 'im. — ^V. H. Wilkinson. Lnmi- 

 noeity from heat does not imply burning away or combustion. You 

 may suppose those other ideas correct, though, probably, they are 

 not so. — A Stonebheakeb, J. C. S. Thanks, but method rather 

 cumbrous for the work done. — F. S. L. It is not necessary, in the 

 ■squirrel puzzle, that the squirrel be rigidly attached to the man. 

 The squirrel's rotation, like the madness of the famous dog, is 

 understood to have been intended merely " to suit his private ends." 

 — A. Fbaxcis. Now. — A. B., S. J., R. Willing. Subject too 

 abstruse for explanation in these columns. — T. A. Would only 

 confuse our readers.— F. Malkin, Polaris. H. is honest, though 

 mad ; the other ia neither. — W. H. Lloyd., Reader of " Know- 

 ledge," R. W. W.— JusTiTiA Omnibv.s. Of course, " Mad Tom's " 

 paradox is but a joke. — Long Tom. Tour letter about Mad Tom 

 and H. is amusing ; and I would insert it ; but space is cramped, 

 ■and — would you believe it ? — there are some who take such letters 

 for solemn earnest, and gravely rebuke me for inserting them. — 

 Canes Vesatici. Will trj-, but we are low-priced, and cannot 

 afford BO much that way as papers like the one j-ou name, not only 

 lugh-pricpd, but not giving Isalf-a-page weekly of original matter. 

 Set onr ten columns weekly of paid matter against illustrations 

 (without e.tception borrowed), and you will admit that for one- 

 third the i>rice wo give a fairer eqnivalent. — G. B. In Knowledge 

 for May 21. — J. R. Clafham. Quite agree with yon that he could, 

 if he would, have given very interesting matter, at very little 

 trouble and considerable profit to himself. But there are those who 

 deem it an offence to point out errors in their views — a mortal 

 offence to prove their [views erroneous. — W. Miller. On return to 

 town will prepare a paper on the subject. — R. L. L., A. Wishabt, 

 and many others. Have asked our assistant who spoke so highly 

 to us of the Loisettian system to say whether he is still satisfied of 

 its value. — Incredulitas. Cannot reply, of my o^vn knowledge, 

 about the Loisettian system. — P. J. L. The lady who wrote the 

 article on the Divided Skirt would not care to have her photo- 

 graph taken for public sale. But in any case it would show nothing 

 of the divided skirt, which is whollv concealed under the skirt of 



the dress — this skirt not being divided. — G. J. Padbuby. That is a 

 matter for the imblisliers. — M. R. Doubtless, granted a sufficient 

 supply of heat, or other form of energy for decomposing ■water, 

 water would be an inexhaustible fuel-snpply. — II. Godwin. C. F. 

 Hodgson 4 Son, Goughsqunre, Fleet-street. — H. Vallance. First 

 deal puts card in middle seven, second puts it in middle three, third 

 makes it the middle card. — F. B. Allen, B. Holt, Professor 

 E. J. H., Ph.D. Our readers so nearly unanimous, that to balance 

 your one letter in favour of stays wo ought to put in, at least, a 

 hundred against them, for which wo have not space. — Rov. Terence 

 O'Flanaoan. Regret you were disappointed ; but question is not 

 comment. Imagine the Padre Sccclii would have opened his eyes 

 had ho heard that the Roman Catholic Church maintains, or you 

 seem to imply, that the earth is flat. You mistake, however, in 

 supposing that Galileo advanced the contrary. It was not neces- 

 sary. For no men of science in his time needed to be told that the 

 earth is a globe. — W. RowE. Know nothing on either point. — One 

 Already Reformed in Dbe.ss. Surely very few girls have the 

 barrel shape you speak of. All in my own household look at least 

 as shapely, and far more graceful, since adopting tho reformed 

 dress. — Chev. De L., E. C. Blscoe. Tho testimonial is true as far 

 as it goes; but it does not go very far. 



^ur fflaa&i'gt Column. 



By " Five op Clubs." 



THE ECHO OF THE SIGNAL. 



WHEN trumps have been signalled by your partner, and you 

 have yourself length in trumps, it is most desirable to let 

 hini know as much, that ho may not, by continuing to lead trumps, 

 extract two for one or none of the adversaries'. It often happens 

 that you are not able to indicate length in trumps, under these cir- 

 cumstances, by your return lead ; or the lead of trumps may be 

 delayed, and you may wish to indicate your^trump strength at once. 

 Under such circumstances you should " echo " the signal, if you 

 have an opportunity of so doing ; that is, you should play an un- 

 necessarily high card before a low one, in any suit, trumps or plain, 

 in which you may be able thus to indicate the possession of four 

 trumps at least. This " echo " signal, in fact, has, like the signal 

 for trumps, its negative as well as its positive aspect. Just as not 

 signalling for trumps when you have the opi)ortunity means that 

 you have not more than a certain degree of strength in trumps and 

 plain suits combined, so not to echo the signal, if you have the 

 chance, means that you have not more than three trumps. 



You cannot readily echo, as you can signal, by the discard, for 

 when your partner lias signalled, and the opponents lead a suit 

 which you can ruff, you would not discard from a plain suit, but 

 take the trick, whether you held more or fewer than four trumps, 

 in order that you might lead trumps in response to the signal. 



It is well to notice, in regard both to tlio si-jnal and to the echo, 

 that, failing to observe either form of signal on the adversaries' 

 part, or the absence of either when there has been an opportunity 

 for its display, is as mischievous as failing to notice such signals 

 or their absence in your partner's play. Thus, suppose one of 

 the adversaries leads trumps, really in response to his partner's 

 signal, but as yon suppose, not having noticed the signal, 

 from his own strength ; if the chance of forcing him arrives, yon 

 seize it, thereby playing his game, or when yon should force the 

 hand of the partner who signalled you, omit to do so, supposing 

 him to be weak in trumps. In fact, failing to notice the play of 

 the adversaries with regard to signal is ajit to prove a more dan- 

 gerous error than failing to notice yonr partner's signal ; for in one 

 case, your play, in consequence of your carelessness is weak and 

 incorrect in presence of trump strength of the adversaries, the 

 consequences of which can hardly fail to be disastrous ; in the 

 other case, yon fail properly to support your partner, but his 

 trump strength is there all the time, and will probably save yon at 

 least from irremediable disaster. In tho latter case, you may pro- 

 bably fail to make a game which might have been won, and despite 

 the saying that the cards never forgive, you may retrieve the error 

 in Imlf the number of events. But in the other case, you are very 

 likely to lose a game wliich might have been saved, and there is no 

 way of restoring a game which has been lost. 



It is hardly necessary to observe that whether a player approves 

 or not of the general principle of signalling, wherever required, at 

 Whist, he must play at a disadvantage if ho fails to employ the 

 system against players who studiously employ it. But if your 

 partner is habitually careless with regard to tho signal, while your 

 opponents are observant, it is well to avoid signals of all sorts, 

 since they inform the adversaries, and tell your partner nothing. 

 (To be continued.) 



