278 



NATURE 



[Jlly i8, 1895 



specially made, the bright sunshine amounted 101634 hour». 

 thT morning is usually bright until about eleven o clock then 

 clouds con,? up and continue unt.l about four o clock bj s.x 

 o'dock the sky is generally cloudless. Except durmg the north- 

 J:^' monsoon.^ nfgh- «hich is wholly cloudy is almost unknown^^ 

 Under these highly advantageous conditions, 'here is oery 

 pr.vspect that the establishment of this observatory will resuU in 

 \ grc^t gain to astronomy, especially in the department of solar 

 physics. . 



Star C\T^LOGlES.-An admirable r^sumi d the history' of 

 slJ<^ulo^urnE?from the pen of Mdlle Klumpke the g,.rted 

 d^?ressofthe/;Kr«"</<-.'^»/<'""-«"f "^^ l'*"^ Observatory. 

 apXrHn the current numl^r of the /?»//</"' of the Astr..- 



nEl Society of France. From -;-'™'-"'^ ^by sole im 

 three great eptjchs may be recognised, each marked b> some im- 

 portant discover.-. The first eixKh is that in which the line o 

 ^ion is defined by hollow cylinders or by an alidade, and 

 :.rnds from the time of IlipVrchus to ^^^ -' ^:^^f^^^ 

 comiuises the catalogues of ilipiJarchus, Ptolemy, Llugh-Beigh, 

 and T xho Brahe. The catalogue of Hevelius, though drawn 

 up fro,^ observations with the naked eye, marks a trans, ion 

 "«riod as he took advantage of the application of the pendulum 

 to the regulation of clocks. , r ,u 1 ,i„ 



The second epoch is marked by the applicatH,n of the te le- 

 sco,^ for accurate sighting of the heavenly bodies, and t^^^e 

 employment of the siderc-al clock. This period commenced » 

 Fla'msteed, and extends even to the present "■"«=•, I" ^f^'f 

 eix>ch the photographic plate replaces the eye. tnthiisi, , f> r 

 this method of cataloguing the ^'"^"mmenced with th k 

 results obtained by the H^nO-S but it should not be forgotten 

 that .-us far l«ck a/ 1865, Rutherford obtained Photographs of 

 stars down to the ninth magnitude, and that he clearly fore^w 

 the .dvamages to be derived from the- photogn.phic metho.f 

 \ll the world knows now that a great photographic chart of the 

 heavens, initiated by the late Admiral Mouchez., ^^^^^^^^ 

 con.struction, eighteen observatories partici|Mting in ihc gigantic 

 under^king. -Mdlle. Klumpke estimates that this imernational 

 catal.nrue will contain upwards of three millions of stars. 



Th^photographic method, however, <loes not yet appear to 

 be without imperfections, as the impressions on the negatives are 

 not certainly .K-rmancnt. In a communtcation to the editor ol 

 the Ohcrfltory, Dr. Isaac Roberts gives some figures relating to 

 the dusapi«arance of the smaller images in the course of years ; 

 in one nc^'vc no less than 130 out of 364 star images had d,s- 

 amxrared in nine and a quarter years. Hence ,t isimpor ant that 

 aTshort a time as possible should elapse between the •a'j'ng o a 

 photograph and its reduction, or, better still, ,ts manifoldtng by 

 some carbon process. 



THE PI ACE OF A KG OX AMONG THE 

 ELEMENTS. 

 TIIK ix.sition of argon in a classification of the elements 

 A deilcnding on atomic weights ha.s been recently defined by 

 C ] Kee<l ( /oiinial of the hranklin InstiluU, July). The 

 elements are a.ssigned (wsitions on a plane determined by 

 aLs issa- prop<,rtional to their atomic weights ami ordinates 

 .>roporti..nal to their ^alency. Oxygen is a-ssumed to have an 

 electronegative valency 2, and the valency of other elements is 

 referred to this as standard ; electro-iMsitive valency is 

 ,„ca.sure<l upwards, electro-negative downwards from the zero- 

 axis. Under these conditions most of the e ements fall on a 

 ix-culUr series of double, equidistant, i«rallel .straight lines 

 connecting elements in order of their atomic weights and 

 sei«rated allernatily l>y distances corresponding to one and 

 sixteen units of atomic weight respectively. 



If the plane 1«.- now fol.le.l into acylmder w,lh axis l>arallel to 

 the at>scisvi' and a circumference ..f eight units of valency, it is 

 found that ihe uptK.r and lower (Kirls of the connecting lines 

 coincide; ihe vshole of these lines then form a i«irallel i>air of 

 M«ral» on the surface of the cylinder, and valency in angular 

 mea.«ure U-r-nvs direrlly pro|)f)rtii>nal to atomic weight. 



The re ■ «hich Ihe elementsof l.iweralomic weight 



'all oltei.i 1 "f Ihe (nrallel spirals is very sinking, but 



this regul .laiiilained among elements <if high atomic 



weight. II ...ns <K:curring with n,o.st of the elements 



of which 'I weight ranges from loo to 130. The ax,.s 



of .iKiniic weights repie^-nls the valency -I- o or -t- 8 and is cut 

 l.y Ihe double »pir.il 11, fifteen jxiinls. There should then \k a 



NO. 1342, VOL. 52] 



group of fifteen elements hav-ing a valency of zero or eight, and 

 their atomic weights should be, respectively. 4. 2°. i^. 52. ob, 

 84, 100, 116, 132, 14S, 164. 180, 196. 212. and 228. .Ml th^. 

 known elements appear to In.' grouped together on certain regions 

 of the surface of the cylinder, other parts remaining comixuatively 

 bare. The only menibers of this family to lie expected to occur 

 in terrestrial matter will be those in the inhabited regions ol the 

 cylinder surface. The hyi>othetical elements having atounc 

 weights 20, 36, 84. and 132 are the most necessary from this 

 point of view. . . . 



It seems reasonable to suppose from the peculiar position ol 

 these elements on the border-line between electronegative and 

 electro-positive valencies, that they should be more strongly 

 electro-negative than the corresponding members of the sulplnii 

 eroun, an<l should nevertheless be without valency (or octads). 

 They should, in general, be more volatile than thecovrespomhng 

 members of the sulphur group. As electro-negative valency 

 diminishes in any group with increase of atomic ""S^'"' ' .'^ 

 element 196, if it exists, cannot be expected to be electro- 

 necative. This element should be a volatile metal, heavier and 

 scarcer than gold, an<l capable of easier reduction to the, netallic 

 state ; it should be capable of forming an oxide KU4 or a s;iu 

 K RO, The volatile metal osmiom agrees with the require- 

 ments of this elen,ent very closely. Similarly, ruthenium may 

 possibly be the element too. 



Finally, argon falls naturally into the place of clement 20, and 

 possesse-s, so far as is known, the proi«rties to be expected o 

 [his element in position 20 in the new group. Argon and 

 element 36 should be comparatively abundant m nature, while 

 84 and 132 should be scarce, but not more rare than selenium 



and tellurium. . ,<; r ;, ,.„ 



On Mr. Reed's system, argon should lie element 36 ,1 it be 

 monatomic as now believed, and not 20 as he .-issiimes : Uie 

 actual atomic weight found. 39'9, ^vo"l>l "^•^" ,,'"''''^ ^i,,' ,5 

 possibility of the presence in argon of soine sinall <|uami > ot 

 Llement 84 or element .32. It ,s remarkable also th.it, if 

 helium has the atomic weight 4- it falls naiura ly in ih.s groui , 



i and that its atomic weight .leduced from the observed ^l-.""-'' >> 

 somewhat greater than this number. H th,s diflerence should 



I be due to Ihe presence .if some small quantity of element 84, 

 then the spectroscopic evidence leading to the conclusion that 



' argon and helium contain a common constituent would he 

 explained. 



POCKET GOPHERS OF THE INITED 

 STATES. 

 TN /iulhlin No. 5 of the I'.S. Department of .\giic»ltv,re, 

 i Mr \ern.in Bailey gives an account of the habits and life- 

 hislory of the I'ocket f.ophers of the United ^-Jales, which 

 contains a number of interesting facts and ol«ervalio s .le 1 ed 

 from various sources. These curious little "-S'^-"'; '.;,"" ''','■ 

 ground in burrows which Ihey tunnel in the soil. Whc « irk- 

 ing their way through the earth, they use the upper mcsors ,s 

 L nick to loc^en the ground, while the f.ire-feet are armed «ilh 

 str'^ng curvc-d claws tr .ligging. When a sufilcient quantity of 

 soil h^as accumulated behind an animal, he "'"^'^ "> ''- '"7 ^ 

 and pushes it out in fronl until an opening in the l" >"'■'>'• 

 reached : the earlh is here discharged, and forms a Inllock 



m iar .0 the hills ,hro«n up by moles. Copher l-»r->« «« 

 extended and added to year by year, an<i .he c-'V^^"-- ';"»';" 

 by the hills of .soil brought up to the surface ■"!'''"'• '"^ 

 hiU-rnate,as has been commonly supposed but work stead ly 



hroughot I the winter. They do a great deal <if good m m,xing 

 ,l,c soil, and in .his way are probably' m.ist useful on poor o 

 ,„„n,ltiv;,te<l ground. Hut, .m the o.her han.l, in agr.c.i lu al 

 distric.s .he .animals are highly injurious ; they devour potatoes 

 and other tubers and roots in large quantities, as well as com, 

 wheat, and .ither farm crops; an.l they destroy great nmnbers 

 of fruit trees by gnawing off the roots. . .opher ■"";'«■• =^';° 

 often <lo a great <leal of damage in ine.a. ..w* or on 1'-' V" ^J;^ °' 

 ar.ilicial waler-courses. So great is .he harm '^"^'^^^J '"^^^l^ 

 that in many districts boun.ies have been 'f^c^ for their cap 

 Hire. (Jne of the most striking features of Pocket '"I * ^^* 

 their ,x,s.se.vsion <if cheek lx,uches opening outside he mm Ih. 

 It is commonly supimsed that these pouches are used lor c.irr) 

 ing earth out of iKe burrows; bu. Mr. U.iUy's .nvestigalion* 

 lead him unhesitatingly to the conclusion '"'-l' ''"''j;'^"' ff 

 erroneous; they are used only for carrying food-pieces ol 



