Kov. 



1881.J 



KNOWLEDGE 



79 



easy and prompt, though loss sustaiucJ, favoured by ready obedience 

 of muscular action and short stature. She is less combative than 

 man. (This rule has serious exceptions.) She desij-es to please. 

 Man's mission is to protect and defend. Her disposition to sustain 

 mental and bodily exertion is much less than man's. She is fonder 

 of change, and more fluctuating in opinion. Varium et mutahile 

 semper ftemina. La dunna e inolilc qual piuma al vento. Not 

 by her understanding or mental force, but by her prompt and 

 easily-affected sensibility, is woman eminently adapted to sui-mount 

 maternal suffering ; through affection and pity, to bo interested in 

 children and household cares. Where her heart is touched, a woman 

 will make incredible sacrifices for a lover, a husband, a child, a 

 parent. She is constitutionally fitted to be wife and mother, to 

 '• guide the house," for minutia; of details. A girl of si.\teen makes 

 a better housekeeper than a man of Bixty. Woman is more 

 sedentary than man. Her disposition is milder. She is less 

 addicted to great crimes. 



Woman's face resembles the child's in absence of beard, rounded 

 form, smooth skiu, and brilliant complexion. The infantile type of 

 head appears in smalluess of features relative to skull, and jicrpen- 

 dicular forehead. Welcker says, woman displays ortlionietopy 

 (perpendicular forehead) and a decided tendency to prognathism. 

 I have seen both combined in the same skull, though a retreating 

 forehead and projecting jaws generally go together; and ortho- 

 metopy generally accompanies orthognathism. Camper's facial 

 angle is a very uncertain measure of intelligence ; according to it 

 alone, the child would stand higher than the man. " If skulls are 

 ranged according to Camper's angle, the infant's skull, contrasted 

 with any animal's, occupies a higher place than the adult's ; but if 

 skulls are ranged according to the ijicreasing angle of the sella, the 

 series stand — man, woman, child, animal." (Welcker.) A front view 

 of head and face is well defined by the outline of an egg. The big 

 end represents the skull, the small end the chin. The egg's short 

 diameter gives the position of the eyes, which bisect the oval. If in 

 man, the part above be greater than that beneath the eyes, it is 

 Dot objectionable, because we associate this excess of coronal 

 elevation with intellectual qualities characteristic of sex. In 

 woman's head, a similar excess in the superior region is a fault in 

 beauty, for which the masculine qualities corresponding to this 

 bead-tyjie do not compensate. Ancient Greek sculptors perfectly 

 understood this important distinction in the cranial contour of the 

 sexes. The female head contrasts well with the lofty, massive 

 square brows of male heads. Of the Venus de Medici, Walker 

 observes -. — " The size of the head is sufficiently small to leave that 

 preponderance to the vital organs in the chest, which makes the 

 nutritive system peculiarly that of woman. This is the first and 

 most striking proof of the profound knowledge of the artist, the 

 principles of whose art taught him that the vast head was cha- 

 racteristic of a very different female personage. Phrenologists 

 have told us that the head of the Venus is too small. They might 

 as well have said that the head of Minerva or the Jupiter is too large, 

 or a hundred other ignorant, inapplicable, or ridiculous pedantries" 

 ("Analysis of Beauty "). The Gradgrind utilitarian school depre- 

 ciate the fine arts. Independently of intellectual pleasure, what 

 actual knowledge in these masterpieces ! Ancient sculptors could 

 learn nothing of beautiful forms from phrenologists. The latter 

 may learn much from ancient sculptors of the influence of sex on 

 mind. 



Nov. 14. J. McGregor Allan. 



SPEED OF ICE-YACHTS.— THE FIFTEEN PUZZLE.— CHEAP 

 TELESCOPE AND MICROSCOPE. — TECHNICAL TERMS 

 RELATING TO TELESCOPES. 



[48] — There are two things in last week's Knowledge that I wish 

 to mention to you ; — 1. In explaining the ice-yacht, you say the 

 parallel wind HG (diagram) will increase the yacht's velocity, 

 which already exceeds that of the u'ind. It seems to me that you do 

 the very thing which you take exception to " Upsilon," doing, viz., 

 take it for granted ; but, perhaps, I may have missed your meaning. 



The other thing (2) is the " Fifteen Puzzle." I am sm-e many 

 of your readers would like, as well as myself, to hear more of this 

 puzzle; what "the true won position" means; in fact, to explain 

 what the puzzle means, as I candidly confess I have never heard of 

 it before. 



There is another matter I wish you would help me in. For some 

 time past I have wished to become the possessor of a telescope and 

 a microscope, but have not been able to see my way to doing so. I 

 could afford to give abont £5 each in purchasing them. With 

 regai-d to the microscope, my ambition is to take, were it years 

 hence, a degree, both in surgery and medicine. I know that a 

 monocular is best suited for histological work ; but I should like 

 the time that I would spend at the microscope to materially 



serve me aftenvards. Which should I purchase, a binocular or 

 monocular ? Could I get one to serve my purpose for £5, or would 

 I require to pay more ? Then, as for the telescope, I am puzzled 

 at the various technical terms used in the magazines I come across, 

 for instance : — (1), Equatorial telescope ; (2), astronomical tele- 

 scope; (3), terrestrial eyepiece; (4), reflector; (5), refractor; 

 (6), 11-iuch achromatic; (7), 6J-inch object-glass; (8), 9J-inch 

 mirror; (0), altazimuth stand; (10), equatorial mountings and 

 divided circles, &c. I shall feel obliged if you will tell me what to 

 purchase and whebe. I should like one that would do some good 

 work for me, and repay me the cost in knowledge obtained. I may 

 add that I have done my pait by getting you another subscriber, 

 and I sincerely wish Knowledge success. — Tours, &c., Twenty. 



[The explanation at p. 36 shows that there remains a driving wind 

 whose velocity is represented by HG when the yacht's velocity is 

 represented by CE, or is greater than that of the actual wind FE. 

 A fortiori, there is a di'iving wind for all smaller velocities. Starting 

 from rest under the action of a wind in the quarter represented by 

 FE, the yacht will travel with constantly-increasing velocity until 

 the di'iving force is just balanced by frictional resistance, and it is 

 shown at p. 36 that even when a velocity exceeding that of the wind 

 has been attained, a di-iving wind remains, wliich may be quite suffi- 

 cient to do more than merely maintain the speed attained. Suppose, 

 for instance, that FE in Fig. 2, p. 36, represents a 40-knot breeze, 

 then HG represents (it will be found, on measurement), a six-knot 

 breeze. Now, an ice-yacht moves freely from rest under a six-knot 

 stern wind, so that the velocity of the ice-yacht under the conditions 

 illustrated in Fig. 2 would still increase, though CE corresponds to 

 a velocity of more than 50 knots per hour. 



I supposed every one knew the Fifteen Puzzle. It consists simply 

 of a square space, witliin which are placed, first, sixteen square 

 blocks, numbered in order from 1 to 16. 

 Block 16 is removed. The rest are 

 placed in any random position within 

 the square space ; and the puzzle is, by 

 sliding the blocks successively into the 

 vacant square which remains after each 

 sliding motion, to get them into the 

 order sho«ni in the adjacent figure. A 

 prize is said to have been offered in 

 America to any one wlio should bring 

 the blocks into this position — called the 

 won position — starting from a position differing only from the 

 "won position" in having the three blocks in the fourth line 

 an'anged 13, 15, II, instead of 13, 14, 15 (a position which has 

 been called the " lost position "), and thousands wasted hours on 

 hours of their time in the attempt to do this impossible thing. 

 Some said they had done it, but were assuredly mistaken. Others 

 thought they had satisfied the conditions of the problem by getting 

 some such arrangement as these ; — 



But the true won position never can be obtained from the lost 

 position. The problem, however, like squaring the circle, trisecting 

 an angle, duplicating the cube, and finding the perpetual motion, 

 has had a singular charm for many, and especially for those to 

 whom the word impossible is as a red rag to a turkey. 



The question relating to telescopes and microscopes I must leave 

 others to answer ; I have never possessed a £5 telescope, and have 

 but little idea what an instrument can be made to do at that price. 



The technical terms mentioned by " Twenty " are no more 

 mysterious than the terms binocular (for two eyes), and monocular 

 (for one eye), which he uses himself. An astronomical telescope is 

 one which shows objects inverted (avoiding the loss of light which 

 results from use of lenses for making the object appear upright) ; a 

 terrestrial eye-piece is the tube (next the eye) containing such 

 lenses ; it is sometimes called an erecting eye-piece ; an equatorial 

 is one which, instead of turning round on an upright axis, and 

 moving upwards and downwards round a horizontal axis, like 

 ordinary teiTcstrial telescopes, is carried round an axis directed to 

 the pole of the heavens, moving also on another axis, so as to be 

 inclinable at any angle to the polar axis; and so forth. But any 

 guide to the use of the telescope explains these points. We may 

 presently publish in these pages some simple papers on such 

 matters. — Ed.] 



