672 



IMIY-K x PROGRESS <>r. IN 



ing liquid air ( 190 ('.). Htid . n.-n 



. |*-r cent. fr.-iu the 



ordinary temi*Taturv to I In- lo\ie-t u--d. Murray 

 (Edinburg 



f form f < ..n-tant-\olutii. air thermometer. 

 which -l>" pre-ure ilint-tlv and may be 



graduated in tem|.erature degrees i'h- !.!. 



Mir.- of the air in tin- Lull), and In n. 6 it- lciii|Hra- 

 turv. i- mea-ured dir.t-tly b\ the height ..f a col- 

 umn of mercurv. the aiiiupheric pressure i 

 dimimtt.-d by adjusting an auxiliary mo 



. 



-hows that Li' fhatdier's thermo- 

 lemrn( may ! applied to the continuous <. 

 urvinent of furnace tcm|craturcs, thus possessing 



jul\ r . "iiim'ii pv i 



-/r/ri7y. Stran- o fAtli tin Lincei." VI. 

 page '.. rmined tin- thermal conductivity of 



Ice by new method. Mid tinls that it varies ac- 



Mg lo the direction. In homogeneous. amor- 

 phous ice th.- values for tin- vertical ami h<>n/oiital 



tions were practically rqua! o-:;rj ; , ; ..i .. 

 I -lit homogeneous DOOMDoraooQI ice gave ' 

 au.i 0- 



Coo/im/. Slant mi (London Royal Society. May 

 iiat the lu-at t rail-mil led fmni thr \\all- 

 of a heated metal piie to colder wain- flowing 

 through it is inde|H'ndent of the |nvuiv. pi-op,, r- 

 to range of tcmj>eraturc between pip.- ami 

 water, approximately pn.port ionatdy to the veloc- 

 ity of flow, ami projortional to a function of the 

 viscosity. Brush (American Association), in an 

 investigation of the transmission of radiant heat 

 by gases at \:, -arcs. finds that hulong 



ami iVl it *s " sixth law," that the cooling p.-v\. 

 a fluid diminishes m geometrical pn.^re ion wln-n 

 i-ioii diminishe> in geometrical pro.irre inn. 

 is only approximately true with a large balloon, 

 and at pressures from a few millimetre^ upward: 

 that th.-re i- no -ngge -tioji of it win-re a small bal- 

 loon is u-M-d : and at small pressures it does not ob- 

 tain with either lar^.- or small balloons; he found 

 that in a small balloon the cooling effect of the laM 

 millimetre of air is nearly ten tun.- - that 



f all the rest, op to atmospheric piv-Miiv. i-.mijined. 



. <i/l .\>>*<>,i>t,,<. r.owman (Am.-ter- 

 dam Royal Academy of Science*. March 27), in 

 measurement- of the .-mi ion and aloorption of 

 glass and quart/ at different leiii|ieraiiiiv-. made 



with a moliflel radio-miorometer. tind- for plates 



one millimetre thick that both the .mi--in and 

 absorption curves of -la-- r.-ach a maximum al 

 4*6 p. shifting but little with temjeratnre. The 

 quotient of emi ion l>y ab-orption yields a cur\.- 

 wlnise maximum i- further toward the lesser wave 

 lengths. The emission and absorption of quarts OOF* 

 respond, both exhibit ing the ^amc downward bends. 



1'hilo-ophical 



n. 26) has devised a v. r\ - n-iii\c motor 

 that i- driv.-n b\ c.,nvecti.m current-. It be-ins to 



work on i-xi-o'iin- to ordinary daylight, or even to 



light. Its speed is affected by barometric and 

 conditions, and it i> hence capable of 

 ting these. It can al-xilic adapted 



I worked by radiant heat 



that passes through a glass c>. riasi i- not 



heateil. but the metaJ surfaces of the in-tninn-nt 



are, and air i- consequently exp . th- m-.t-.r 



H! on'the L'la-. The resulting 



differeiKv of temiH-rat ur. -. t - up ...nvection cur- 

 rents t : fie motor. 



/^c Heat. Wa i-.vorth (* American Journal 



that, in determining 



i.-at l>y the method <f mixture-, the calorime- 

 ter should be small and th. : tin- -olid 



large, while the initial temperature of the latter 

 should be high. He describes a new form of calo- 



rimeter in which the body i- in a small 



sheet ki laid in an inclined 



tube that servet aa A beating chamber. Thi> pi<>- 



\eiil- lo-> of heat and iH-rnnts expcriinentat ion on 

 small fragments, ('allendar and Names (l>riti-li 



AsSOf'iat loin ha\e d<-\ l-ed a Hew method of ob- 



taining tl. heal of a liquid. An electric 



it i- pa ed t lirougli a line t nbe t hrnigh which 



the liquid i- flowing until the tempera! ure dill, i - 



II the end- IH-I-OIIH- 



n iledueed fr>m thi- ditlcrciicc and 



the liiplid and iMinkcrlcy 



</////.! Iliea-ure the sj.ecilic heat of salUCaleil >tc;ill| 



i ing it throii-h a porou- plug and thu- siip.-r- 

 heat i! ! Id-lot i I'ai i- Academy 



Jan. IS) shows, in a /'.*///// of result- obtained for 

 the -pecilic heat-of the elementary gases, that the-.- 

 fall into four groin.-. c,mpn- ti\el\ the 



nionatomic gases (helium, argon, and 

 diatomic gases other than halo-en-, tin- hai< 

 and tetratomic ga- plio-ph,,rn- a: 



s -nic. 



/tii'liiinf Hi l. --Rubens and Nichol-. i \\ 

 mann's " Annalen." March) have obtained hea 1 

 of hitherto unreconled len-lh by filtering out 

 r.-d rays by three successive reflection! from fluor- 

 -par or rock salt, the soince l.ein- a healed la\ 



the sail).' sllb-laiice. The flllorite relleclion- 



M-.") p. which an- :!() time- a- long a- the 

 : vi-ible n-d ra\-. Reckonim; 1> 

 the-e ra\- are midvvav between the shortest ultra- 

 violet ua\e- and the shorti-l observed electric 

 - ((i millimetres). K. lie. -t ions from r.<'k -alt 

 waves of 50/n. 



Light. Tlnni-i/. |\Mrle\Ve- (Alll-li-rdam Ro\al 



Academy of S< -i. DO) I, M. iiat under 



certain conditions some of the oscillations possible 

 in a mechanism of several degrees of freedom are 

 of abnormal inagnil 'ide. and h> that the-e 



may play an important part in the vibration-, of 

 light 



AbHHrnliun. Agafoiioff. of St. Petersburg i" Ar- 

 chive.- des Science! l'h\-ique> et Naturelles." l\'. 



page 2). has investigated the ab-orpti-.n of ultra- 

 violet light by cry-laK and finds that amon. 

 substances oiilv '2 tourmaline and hemimdliiic 

 acid exhibit (lilT.-i, ,!.-<.rption accrding 



to direct ion of polari/at ion of the light. The thick- 

 ness of the section n-.-d -eems t<> have lit t |c influ- 



enc the limit of wave length at which al 



lion liegins. Organic substances ab-.rli powerfully, 

 in compari-on with inorganic, and this suggests 

 that ultra-violet light i- more ab-orbed by complex 

 than by simple molecule-. 



-/. Lamb (Mancli. and 



Philosophical Sociei . ha- examined math- 



ematically the selective total reflection that take- 

 place at the boundary of a medium havin-a peri- 

 odic discontinuity of struct urc. He find- that rela- 

 tively short iraves may be transmitted fredy. n 

 the wave length happen- to fall within certain nar- 

 rowly defnu-d interval-. and Stan-field 

 find by u-ing a modified n-- 



fractometer that the retardation in phase of light 

 on reflection from thick silver is three <juartei 

 wave length. 



-ay and Ti don Ro\al 



rared l.y Rayl.-i-h's inter- 

 ference method the refract ivities of Var 

 taking that of air as unity, with the foil*. wing re- 

 sult-: 



D 0-9598 



Carbon dioxide 15816 



Hvlr..L-. -N . 0-4788 



... 



The refract ivity of air. calculated from those of 

 its con-titm-nt-. "did not a-iee with experiment, 

 and the same result was obtained with other gaaeouf 



