May, 1906J 



KNOWLEDGE & SCIENTIFIC NEWS. 



423 



5 inches fcx;us was used, all the photographs were taken 

 with the same telescope, viz., a i2i-inch reflector having 

 a focal length of 10 feet. This instrument, which was 

 formerly used by the writer, is now in the hands of Mr. 

 Maciachlan, of Largs, who made the original exposures 

 from which Figs. 8, 11, and 12 have been produced. It 

 will be understood that all the original negatives were 

 subsequently enlarged with the camera, and details of 

 the method employed will be given in another paper. 



Fig. 7 shows four photographs of the planet \'enus, 

 taken January 13, 17, 28, and 30, 1902, at the primary 

 focus of the mirror. A slow plate was used, and the 

 duration of exposure was about half a second. The 

 images were afterwards mounted on a strip of glass 

 and enlarged together. 



Fig. 8 is a photograph of the planet Jupiter, the 

 primary image in this instance being directly enlarged 

 in the telescope wth a low-power Ramsden eve-piece. 

 The exposure given was two seconds, and the plate de- 

 veloped with a solution of normal strength. 



Fig. g was taken at the primary focus of the mirror, 

 the lunar terminator receiving three times the amount 

 of exposure given to the rest of the disc. (See method 

 No. I referred to under " Lunar Photography.") 



Fig. 10 was taken during the last phase of the lunar 

 eclipse of April 11, 1903. The exposure in this case 

 also was made at the primary focus. 



In the production of Figs. 11 and 12 a Ramsden eye- 

 piece was used in the telescope to enlarge a portion of 

 the primary image, the exposure in each instance being 

 10 seconds. Those who are acquainted with lunar 

 typography will readily recognise the regions depicted 

 on the prints. Fig. 1 1 shows a portion of the termina- 

 tor in the vicinity of the craters Bullialdus and Tvcho, 

 while Fig. 12 is a photograph of the well-known crater 

 Copernicus and the surrounding region. 

 (To he continued.) 



Simple Rule for Squaring any Number. 



Rules for simplifying arithmetical calculations have 

 often been published. The following simple method of 

 squaring any number is somewhat interesting. It 

 ought probably to be taught to beginners in connection 

 with extraction of square root of which it is the con- 

 verse, and an instructive exerci.se is afforded by 

 squaring numbers by this method and verifying (he 

 correctness of the answer by long multiplication. 



Suppose it is required to find the square of 

 5342.7198, the multiplications being carried to four 

 decimal places; the process stands as follows : — 

 53427198 X 5342719S 

 5000 X 5000 = 25030OCO 



103 X 3 = 3cg 



1064 X 4 = 4256 



10682 X 2 = 21364 



10684-7 X '7 = 747929 



10685-41 X I = 106-8541 



10685-4 X 9 = 96-1689 



10685 X 8 = 8-5:83 



2854.1654-S613 

 \\'ith a liltle practice, the successive lines of multi- 

 plication could be written down nicntally without w-rit- 

 ing down the successive niultiplicands and multipliers. 

 Xumbfrs mav be easily cubed or raised to any desired 

 j)in\or by a kind of reversed Horner's process, very 

 similar in principle to the above, but it is doubtful how 

 far any further extensions of the method are suited for 

 teaching purpo.ses. G. H. B. 



Spitzbergerv and its 

 Whale Fishery. 



By T. Southwell, F.Z.S. 



It is only of late years that anything like order has 

 been established in the classification of, or any import- 

 ant advance made in, our knowledge of the distribution 

 and life history of the members of the important family 

 of marine mammals known as the Cetacea, or whales 

 and dolphins, and this especially applies to the whale- 

 bone whales of the northern hemisphere. It will 

 hardly be believed that although the great .Arctic Right 

 Whale has been known since the year 1610 and many 

 thousands of them killed, so rare is the skeleton of this 

 animal and so difficult for various reasons to obtain, 

 that it is still a desideratum to our Xational Museum; 

 but owing to the establishment in Northern Europe and 

 .■\nierica of whaling stations for the pursuit and capture 

 of the giant Fin Whales (Balaenopteridee), rendered 

 possible by the discovery and perfecting of a mode of 

 attacking tht-m by explosive harpoons, the invention of 

 Herr Foyn, a Norwegian whaler, abundant material 

 has been rendered available for their study and accurate 

 description. Still it is very remarkable how slow the 

 general public is to appreciate this advance, and how 

 singularly they fail to distinguish between the various 

 distinctive branches into which the family is divided, 

 even confounding, as will be seen below, those armed 

 with teeth with those furnished with the remarkable 

 appendage know'n as baleen, or whalebone, the feature 

 on which the main division of the order is based, 

 namelv, Mvstacoceti, or \\'halebone w'hales, and 

 Odontoceti, or those furnished with teeth. 



Even in the writings of acknowledged authorities we 

 sometimes meet with strange statements. For instance, 

 in one text book we are informed that a Right Whale 

 mav produce several " tons " of whalebone, a most 

 liberal allowance, and at the present price of ^.2,250 

 per ton, a very valuable asset; another authority states 

 that the Right Whale, though found in the seas on botli 

 sides of Greenland, passing freely from one side to the 

 other, is never seen so far south as Cape Farewell. 

 The first statement is doubtless due to the intervention 

 of one of th(3se evil spirits specially allocated to the office 

 of the printer, who wickedly substituted the word 

 " ton " in the place of hundredweight; the second is 

 probably an oversight, for its author was one of our 

 most accomplished cetologists. That the Right W'hale 

 is (or was) found on both sides of Greenland is un- 

 doubtedly true, but as it never descends so far south as 

 Cape Farewell it is difficult to understand how it can 

 pass frei'ly from one sea to the other. .\ charming writer 

 and a leader in the world of science evidently never 

 acquainted him.self with the learned researches of Prof. 

 Eschricht, for he adheres to the old belief that the 

 whale formerly hunted by the Basques in the temperate 

 regions of the .Atlantic, through persistent persecution 

 has retreated to the ice-fields of the Polar regions, 

 whereas the speci-.^s inhabiting these two areas are per- 

 fectly distinct. 



Of late jjersonally-conducted tours have been extended 

 even to the icy regions of Spitzbergcn, and, of course, 

 the travellers to this No-man's Land have fa\ourcd their 

 les.> adventurous bretiiren, by means of the public press, 

 with the results of their peregrinations; and as the 

 tourist is almost invariably furnished with a " Kodak," 

 the illustrations to their articles are, as a rule, excellent. 



