3S 



• KNOWLEDGE • 



[Nov. 11, 1881. 



Iiuiiili-odlli of tlicm\iltitiidinnu!i iiositionsof wliich thopuzzli' admits 

 were occupied ninDiig all tho po!<iii(>nH (set up, nttninod, or pofsod 

 thruiif;li) ill the thoiiHnnds of iiiillioiiR of trials tlioKo iiiiilioDa made. 



If " Ijosg" ia not content, let him try tlio easier task of briiij^inf; 

 oi^lit blocks from tlio position slion-n in Fig. 2 to that shown in 

 Fig. 3. 



FiR. 2. Fig. 3. 



This is a lesii complicated task than that of the original "Boss" 



puzzle, for instead of more than 10,000,000, there are only 181,4'10 



losing positions in a nine-square puzzle. Or he might trj' to cliange 



from 



! 1 I 2 

 4 I 5 



There are only 360 losing positions in a six-square puzzle. Or finally 



where ho has only twelve 



losing positions to trouble him. He will see nt once that the last 

 task is an impossible one ; but he may rest assmcd it is not more 

 completely so than the others, and it wastes much less time. — Ed.] 



(BmYit$. 



[1] — Ultima Tnri.E. — One often finds the expression Vltima 

 Thule used as if indicating the remotest known regions of the earth. 

 Where in classical authors is this expression used, and in what 

 sense? — Alpha Sigma. 



[2]— A Fifteen Puzzle.— Most of your readers are no doubt 

 familiar with the puzzle how to send out fifteen school-girls walking, 

 three and three, so that during seven successive walks no two of 

 them sliall be more than once in the same set of three. Is there 

 any mathematical treatment of this puzzle corresponding to the 

 mathematical treatment of jiermutations and combinations ? It 

 seems to me that there should be. For instance, one might begin 

 by showing that nine pei-sons could walk out three and tliree (with 

 the same restriction) for four successive days, and then apply the 

 method of demonstrative induction to show that if 3 {'.in — 1) pei-sons 

 can be arranged to walk ont in the required manner on (3h — 2) 

 different days, then also 3 (2n x 1) persons may be arranged in the 

 required way on (3n xl) different days. It will be obvious that 

 the number of persons must be of the form 3 (2«±1) ; that is, tlu-ee 

 times some odd number. The successive numbers to bo dealt with 

 are, therefore, 3, 9, 15, 21, ic, and the number of days in which 

 the three can go out in the required way arc respectively 1, 4, 7, 10, 

 &c. — BlSTICUS. 



[3]— Flight of Bikds. — Is it the case or not, that the flight of 

 birds is greatly aided by the presence of warm, and, therefore, light 

 air in the air passages of the bones ? — AiiEiAL. 



[4]— The Eabth's Inclixation.— In diagrams explaining the 

 season's differences, the figure of the earth is shown to rotate on an 

 oblique axis. Were it to rotate on an upright axis, would not per- 

 petual summer reign at the poles, mth greater heat at the equator ? 



MOONSTEDCK. 



[5]— Hot Wi.vns, Cause of ?— The difficulty is as to the force 

 from front or bock which will overbalance the tendency to rise over 

 the hot area. Take the case of a Mediterranean sirocco, why is 

 there not rather an iiii-ush to the hot sandy plains ? — L. S. 



^[C] — Lying To. — Wanted, diagram of forces when a ship lies to, 

 1° under sale, 2° under steam. — L.S. 



[7] — Flying Bridge. — Wanted, diagram of foi-ce.i, arrangement 

 of rubber, position of ropes, when tho vessel has passed the middle 

 of the river. — L. S. 



[SJ — Volume of Sphere. — Is there any simple vmy of showing 

 that the volume of a sphere is two-thirds that of the enclosing 

 cylinder I-' — AncniMEnEAN. 



[9] Srx-i>iAL. — Can any of the readers of Kxowleiice dcscrib* 

 any method of constructing a sun-dial by which the error arising 

 from the shadow not being sharj) may be got rid of ? — Bolab Tike. 



[10] The Zoetrope.— In the zoetropc wo gel a series of picturec 

 of a moving body, showing it in a certain number of jiositions from 

 among the infinite number that it passes through in accomplishing 

 the movement illustrated. Can any one explain how it is that thjt 

 impression conveyed to the mind by this incomplete series of view* 

 is that of continuous motion ? It seems to me that we ought to 

 recognise a certain jcrkiness in the apparent movement. But ill 

 well-arranged xoetropic illustrations no jcrkiness can be noticed. — 

 Zulu. 



A Cabco of Human Bone.s. — New York, Sept. 14. A special 

 from London says : — A great sensation was caused at Bristol hj 

 tho discovery of a cargo of three hundred tons of human bones 

 being discharged there to the order of a local firm engaged ia 

 manufacturing manure. The bones were shipped from Rodosto, at 

 Constantinople, and arc 8U])posed to be the remains principally of 

 the defenders of Plevna. There are complete limbs among the 

 horrible cargo, and in some cases the hair still adheres to the skulls. 

 Peter Cooper saj'S it is a common thing among the British to 

 buy human bones. " In fact, they will take all they can get at any 

 time and from any part of the world. They use them for mano^ 

 ing their lands. I have often heard it said that England was 

 manured with bones taken from tho battle-field of Waterloo. There 

 is no finer to be bad." — Nciv York Herald. 



Science in the Police Couet.* — At Bow-street last week, Mr. 

 Waddy, Q.C., attended before Sir James Ingham, with Mr. Besley 

 and Mr. Bernard Coleridge, to applj- for a summons under the Vivi- 

 section Act, against an eminent professor of science. Special 

 reference was made to the subsections providing for a licence to be 

 granted to any one practising vivisection, and for the administration 

 of some anaesthetic of sufficient power to prevent the animal feeling 

 any pain during the experiment. If pain was likely to continue 

 after the effect of the anaesthetic had ceased, or any serious 

 injury was inflicted on the animal after the experiment, it was 

 to be killed before it had recovered from the effects of tho 

 anaesthetic. When it was desired to extend the experiments. 

 for a lengthened period, it was necessary to procure a certifi- 

 cate authorisirg the extension of the experiments, and tho 

 summons was asked on the ground that this provision in the Act 

 had not been complied with. In support of the application tho 

 learned counsel read extracts from a report in the Lancet ou 

 cerebral localisation, the subject having been brought under the 

 notice of the recent International Medical Congress. One of the 

 speakers was Professor Goltz, who had ex])erimented upon two dogs 

 by exposing the surface of tho animals' brains, and washing away 

 large portions of the substance by subjecting it to the action of a 

 powerful stream of water. With reference to tliis experiment. 

 Professor Ferrier has expressed his views upon the subject and 

 gave details of some experiments he had made upon two monkeys. 

 These animals had been operated upon some months previously, 

 definite motor paralysis being procured in one, and in the other 

 absolnte and perfect deafness. The animals subjected to these ex- 

 periments were jjroduccd by each of the ])rofe.ssor3, Professor Golti 

 asserting that he had removed the gi-eater part of both hemisi)heres, 

 includingall the sii])iK)Scd motor and sensory areas. That the operative 

 procedures to which the animals had been subjected had been exten- 

 sive was quite obvious upon examination of the skulls, large gaps in 

 the continuity of the upper and external walls of which were felt. 

 Saring some clumsiness in its movements, one of the dogs showed 

 but little signs of injuiy. It appeai-ed possessed of considerable in- 

 telligence, and certainly did not suggest to the onlookers t hat it was 

 a dog demented. In startling contrast were the two monkeys ex- 

 hibiied by Professor Ferrier. One of these had been oiH^ratcd upon 

 in the middle of January, the left motor area having been destroyed. 

 There bad resulted from the operation right-sided hemiplegia, wfth 

 conjugate deviation of eyes and head. Facial paralysis was at first 

 well marked, but ceased after a fortnight. From the first there had 

 been paralysis of the right leg, though the animal >vas able to lift 

 it uj). Its arms it had never been able to use. Lately rigiditj- of 

 the muscles of the paralysed limbs had been coming on. The other 

 monkey, as a conseciuencc of jiaralysis of its auditory centres, was 

 apjiarcntly entirely unaffected by loud noises, as by the firing of 

 porcussion-ca])s in close proximity to its head. — From the Times. 



* Tho report would be somewhat clearer if it were not taken 

 throughout fi>r granted that the readers must necessarily be medical 

 students. Why should not paralysis of the right side be written, 

 instead of right-sided hemijdegia P wrj-neck and squinting for " con- 

 jugate deviation of eyes and head?" The " motor and sensory 

 areas " are, of course, those parts of the brain which are supposed 

 to regulate respectively the movements and the sensation. 



