1038 CHEMISTRY AND KNDUBTRY Oct. 85, lee8

stimulntctl by thc discovcrics nindc in pIiysic:i1 science during this century. Tlic properties of niat.ter nnd radiation Iiarc bccn dcscribcd niorc and inorc iri terms of atoms nnd clcctrons, and thc clnssicaI Inws of mcchnnics liy virtuc of tlicir continuity harc bccn found iiindcqrintc to dcscrilJe ntoniic phcnoiiicnz.

Thc first, attempt to introdncc tlic ncccss:iry clciiicnt of discontinuity rcsiiltcd in t,lic olclcr quantiini theory, wliich in csscncc was nn arbitrary rcstrictioii iniposcc‘l on thc cquntions of clnssicnl ~iicchnnics so thnt they niight girc intcgrd solutions, In spitc of the initid succcsscs of this thcory in its p c t i c n l :ipplicatioii, it. coulil not. bc rcgnrdcd :IS more tiinn n tcinpornrp coinproniisc ; nil csplanntioii of tlic nppcnrziiicc nf t l ~ c optical constnnt h in mcchniiical I)roccsscs was Inclting. It sccmcd that, :I coniplctcly IICW ricwpoint was ncccssnry, but, d i n t ivns scarcely to be nrit,icip:itctl wns that PO ninny fundnnicntnlly tliffcrcnt, vicwpoiiits would nppctir in tlic coiirsc of tlic 1:ist fcw years.

Tlic pcriod since 192.1 lins bccii uiiiqucly rich in furnishing fouiitlntioiis on ~vliicli to build our coiiccptioiis of tlic p1iy.sicnl universe. Tlicrc Iinvc apljcnrctl tltc wave nicch:iiiics of ilc 13roglic ; tiic gciicralisatioii of Scliriidingcr, \vhcrcl)y tlic h 1 1 i 1 viour of nil iiitlivitltial pnrticle is found by tlic purely nnnt1icirintic:il process of cletennining tlic c1rur:ictcristic rnltics of R fiintl:iiiietital tliffcrcntinl cr~untion ; t.lic quniituni iiicc1i:inics of IIci~cn- berg I,nzcd oii escliiding froin ntoniic tlicory cwry quantity not susccptiblc to dircct thscrvutioii ; [lie inntric cnlculiis cniploycd by Born a d Jordwi to develop Hciscnbcrgs iiiccliaiiics J and tlic four-fold quaiitisiit ion of tlic :itoink stntcs by Pnuli.

Oiic pliilosopliical cffcct. of the nppcnrancc of tlicse thcorics is t o dcmoristratc tlic iiiiiiiiportaiicc of p1iysic;il pictiircs of tlic mntcrinl uiiiversc ; diffcrcnt ~iiodcls (or no model a t all, e.g., thc resurrection of j)rinciplcs hitlicrto buricd as t,lic f i n d rcsults of rcscarclics in pire mathciiintics), will lend to similar conclusions.

But is tlic pcrsoii lacking 1ii:ithcIiinticid eqiiipiiierit to bc denied on tlint account thc intcllcctunl plcirsiire of npprccinthg thcsc philosophies ? Hans pcrfornis this scrvicc. in t l int hc scts bcfore u s wit,h as little ~niitlicmntics as possil~lc tlic cscnt in1 conccpts u~~cicrlyiiig tlicsc thcorics, trnccs clearly tlicir dcvclopnicnt, nnd gives csnnipics of thcir npplication to practical problems.

Tlic book is lucidly 11-rittcn, and tlic stylc C J ~ S ~ to follo\v, iiicrits \vhicli must bc nbtributcd in pnrt to tlic elliciciit work of tlic trnnslntor. d \vclcomc fcnturc is t,he ndmirnblc sunimary givcii a t tlic beginning.

Altogctlicr the hook is nn csccllciit, int.roduction to tlic siilJjcct, n subjcct tlint is rapidly dc\~cloping, and is in conscqiicncc ditiicult, to treat, in an clciiicnttiry

D I E LEIIItE VOJI l!ltocssI~s IS OItAl’II1SCIlEIt I)AI~S’rI.;L- LUSC:. By I<. REYSCIIER. Sccoiid revised edition. Pp. 74. I3crlin : Julius Springer, 1027. 4.50 riii.

Tlic origiiial cilition 01 13cysohcr’s book, piillislictl in 18111, coiisistcd in an cndcnvour to fiicilit8ntc t h o solu- tion of drying plant problenis by iiicniis of n spccinl dingrnui originidly proposcc‘l for use in calculntioiis on wnter cooling plaut,s by 0. 11. Miiller.

111llnI1cr. JOl lX d. C‘ltAXSTOS

The fundniiicntal tliagrani is oiic in mliicIi tiic total licnts of iiioist nir n t various dcgrccs of saturation arc plottcd against tciiipcrntiircs. This diagram posscsscs tlic advaiitngc of simplicity, and calculations can b e mndc in an cmy and obvious iiiniiiicr. Pot occasioiial work this dingram posscsscs tlic iniportant ndvnntnge of freedoin froiii coiii~~licntions over tile more coniprc- hcnsivc dingrain of JIollicr (%.V.il.I., 1 ‘3?3), on ~i~liich the hook of I~Iirsc11, ‘‘ Dic Trockcntcclrnik,” is bnsetl.

Unfort~unntcly t,liis siiiiill book is niarrcd by sonic tcrriblc inncciirncics, nnrl i t is tlisnppoiiiting to fritl tlint in R sccoiitl edition tlic bluntlcrs slioultl not hnve bccii rectified. In soiiic portions of t,hc book tlic iiiis- takes lire duc to lnclr ol tliorougIuicss in tlic t,licorcticnl trcatiiicnt, a d tliom is n tciidciicy to forin injudicious conclusions froiii ii soiiic\vliiit superficial t;hcoret.icnl rcnsoning. For cxaiiiplc, i t is stntcd 011 page 44 that, drying in countcr-current initst tilways IIC less ccononiical tlinii tlic parallel Ilow iiicthod.

Tlic most serious blot in tlic book, Iio\vcvc!r, consist-5 in C‘haptw XVI, wliicli tlcals with vncIiiiiii drying. In this clinptcr the nirtlior fitarts out with tlic ciitircly fnlsc idea that in n vncuiiiii dryer tJic iintlcrlyiiig process is cxnctly tlic sniiic, froiii a pliysicnl point. of view, ns that, in nn air-drying plniit,, wit,li tlic single iliRcrcncc tilint instead of opmitiiig :it. tfic ntmosphcric pressure n Io\rcr prcssiirc is ciiiployrd.

It niny be t l i n t this iiiistnkc 110s nriscii in tlii: iiiind of tlic author ns tlic result of sttidying tlic small book of I-Inusbrnutl, ’’ Drying by Air nnd Stcani *’ (Clinptcr I\-, English edition, 1912). 3-laving stnrtcd with n false nssuinption, tile writer proccctls to ca lc~ln tc thc tlicriiinl cfficicncy of n racuiini drying process, first of all figuring out. the power rcqiiirctl for uilitibntic comprcssioii of thc iiioist : j r up to thc ntniosplicric prcssurc, and having tlcrivctl n rcsiilt in kilogmiimc iiictrcs, siiiiply coiivcrts this into ciilorics by dividing by tlic mechnnicnl cc~uivalent of Iicnt. This convcrsioii of units of iiicclinni- cnl energy into units of licnt is, of course, not pcrinissiI)le in niiy cnlculation of tlicriiial cconomy.

\\‘iiilst Ilnrisbrniitl, wlio nppnrcntly knc\\. from prncticnl cspcricncc tlic incrits of V ~ C I I I ~ I I I tlrying, nrrircd at, thc conclusion t l int ‘‘ tlryiiig ,iJJ t!acuo \\‘as to bc rccoiiiiiicntlcd from :I tlicorcticnl s t adpo in t oii nll groiiiids,” owing to the false nssitiiiptions iiinilc hc coolcl ouly justify this conclusion by nii nssumption that the nir left tlic npparntiis ;it n consitlcrably lower tciiipcmture t l inn it cntcrcd, niitl by ignoring ttlw po~vcr consiuii~)tion whicli would be iicccssnry.

licysclicr, lio\vcvcr, altliougli not Iinving tlic confidcnce in his cnlculnt~ioiis to clinrgc up t,lic iiicclianical ciicrgy of coiiipcession a t its p ro lw ualac, n ~ d siiiiply taking into ncroiiiit tlic Iicnt cqiiivulcnt, thcn winds 1111 tlic calcnl:itioii by nssiiiiiing sonic cstraordinnrily 1111- practicnl CoiitlitionR witliout cspl~~ioing ho\v such pliysicnl conditions could bc ~niiiutt~incil, nntl arrivcs a t a conclusion t l int drying in V ~ C I I I I I ~ ~ slioultl o~ily bc cmployctl wlicii t,he iiiutcriuls to Iic dried nrc misitivc to tcinpimturcs nLovc tliiit of tlic atmosplicrc.

I-rut1 tlic author talcell tlic t;roublc to cnquirc Iic wonltl have foiiiicl that oiily rarely Iinve wiciiiiln dryiiig plants been cmployt?il d c r sucli contlitioiis, and that Iron1 the point of view of thcriiinl cliiciciicy thc gunrtint;ccs of

OCt. 5 , 1 9 2 9 CHEMISTRY AND INDUSTRY 1U3D

inakcrs iirc sufficient to sliom thnt the vnciiiini drying plaiit is iisiiitlly superior to any forni of nir-drying plant.

This clinpter is such n fsrrngo of iionscnsc that onc is conipellcd to wondcr wlictiicr tlic author Iins cvcr seen a vacuum drying plant. hppnrcntly Iic docs not iintlerstnnd tlie uiitlcrlying principles of tlic system nv a ~\-Iiolc, tlic csnct piirposc ol tlic contlcnscr, or of the vacuum puinp.

A p t from thcsc faults, the book inny 1)c consiclercd ns n uscful oiic in tlic liaiitls of tliosc who linve siifficicnt espcricncc so tliiit t h y cannot bc Icd by tlic nose. Tlie dcscription of tlic grnpliical mcthotls of calculation and thc tlingmins arc ivcll worth tlic pricc cliargctl for the book, but tlic stutlcnt must not cspcct to find any practical data of rcnl valuc in tlic design of plant. Xost theoretical books on drying, ho~scvcr, fnl l short in this respect; they deal with tlic hygroiiietry of the drying plunt, and i t is uiifortiinatc thnt the authors do not takc the trouble to tcst tho mctliods of ctilcula- tion thcy have so laboriously dcvclopctl upon t.lic actual rcsults obtained froni a few dilfcrcnt types of dryiug plant. If this wcrc donc we shoiild rill bc spared tlic cxpcriencc of wading through tcdions cnlculn- tioiis which, wliilst t h y niay bc an escellint iiwntnl disciplinc aiitl scrvc to sliarpcn our critical powrs, do not put us in tlic position systcniaticnlly to develop thc design of drying plant froni pliysicnl principles.

.iZcyscIicr had a n escclleiit opportunity : lic started with a nietliotl of calculation which relieves thc subjcct of niaiiy of its tedious fciitures, and i f Iic lintl applied tlic yardstick of practical cxpcricncc to his calciilatrtl con- clusions Iic ivoultl liavc avoitlcd the scrious niist:ikcs wliicli liuvc rcntlcrctl his book a clangcr to chcniical cngiiiecring education rather tlinn n m i l hclp.

I s u u s r n u L FuirsmiE TECXISIQUIC. By A. I-Isir~rassss. Tmnslntcd from thc Swcdish. Pp. s i i + 393. London : I.:. I3cn11, Ltd., 192'3. 25s.

Opcning with n historical nccoiint of the t h o r y of hcat aiid tlic dcvclopnicnt of furnncc building, tdic niithor, aftcr dcnling with nicnsurcnicnts of tcnipcraturc and thc anioiint, of Iicnt, procccds to discuss, in t-hc third chaptcr, combustion and calorific vnliics. Tlic liest four clinptcrs dcnl with thc production of liigli tcmpcrntnres wit,h fuels, carbonisstion and produccr gas, and tliesc arc followed by cliaptcrs giving a mntlicinnticnl trcatniciit of t,lic transmission of licat and tlic tiinc of hcnt; trtinsmission. Ucforc proccctliiig t o coiisidcr furnncc building iu gcncral and rgcncrntors tuid rcciipcrator8, tlic niovcincnt of hot gases is discusscil. Siibscqiicnt cliaptcrs arc dcvotcd to burners, draught opciiings, working chambers aiid cnlciiltrtioiis rclating to tlic worlting space as well as tlic uinterinls nviiilnblc for furnncc construction, whilst thc supportiug of tlic fiirnacc itself is not forgottcn. In the concluding chapters inforniation is givcn regarding the starting up nnd nttcnt;ion rcqiiired by fnmnccs, as wcll as n coniplctc account of how n h a t bnlnncc for a fiirnacc can bc ilcrivccl.

I n reading through this work, wliicli has bccii t.miis- Intcd from thc Swcdisli, one rcnliscs tlint tlic nuthor is thoroughly fuinilinr with his subject, but nt tlic wnic time onc is compdled t o rcgrct that tho book wns not

HUGU GRIFFITIKS

editcd by soinc one more familiar with English tc:lmicnt writings to cnsiire tlic iisc of ivorcls, csprcssiox, and symbols commonly employed in English technical works. For esainplc, the eniployincnt of r nnd s to indicate teinpcraturcs rcnders tlic cquntions on pp. 96 etc. at first sight nnfamiliar to Englisli rcndcrs. If nttcntion had becn givcu to thcsc points, the book would linvc bcen cnsicr to rend, and tlic vnliinblc information which it contains would be inorc quickly assiniilatcd. Apart from this, R critical rcndcr would havc noticed that sonic figiircs (c.Y., 18, 60, and 86) arc not lettcred to corrcspond with tlic tcst, niitl somc rcfcrcnccs. e.g., on pp. 133 and 263, arc incorrect.

Thc valuc of tlic work would also ha\-e bccn enhanced if nn index had becn providcd. As tlic Englisli liternturc on furnaccs is not very cstcnsivc, the work pins i n iniportnncc, so that it is all tlic inore rcyettahle tha t its litcrary aspect lcavcs so much to bc dcsircd.

TI iE FUStOS I'OIS'C OP COAL ASIC. PMtT I. By J. G. KISG, PIi.D., A. I j w x i G , JLA., and J. 0's. Nrr,r,rorT, 13.S~. Fuel ltcsaircli. Tcc1inic:il Paper No. 23, p. 19. L)cp:irttnciit of Scientific and Indiis- trial licsctirch. Loritlon : 1i.M. Statiuuery Office, 1929. Price Is.

The iinportnncc of tlie fusibility of ash froin various conls, under furnace conditions, niitl tlic ol~jcctionable effccts of fusible clinker, pmticii ldy in modern nicchmii- cnl grates, h:iw caiiscd incrcnsed nttcntion to be devoted to the nictliotls for dctcrmining thc fusion point of n s 1 ~ Tcchnical Paper So. 23 dcsrribcs tlic mctliod used n t the Fuel Rcscnrch Station, and iii iidditioii two iniportant uspccts of tlic problcni hnvc rcccivccl nttcntion, nnnicly an attempt lias bccn iiindc to prcscribc conditions in ordcr t o obtain concordnnt rcsults in diffcrcnt Inbora- torics, and also an cxclinngc of saniplcs bct\\-ccii the Fucl Rcscnrcli Station and tlic Uurcnii of Jlincs, U.S.A., lins becn nindc. Compnrtitirc figiircs nrc givcii for ten IiritisIi and tcn drncrican ashcs under Iniltllj- rcdiicing conditions. l'lic nnnlyses of the aslies arc also givcn.

licfcrring to tlic fusion point rcsiilts obtnincd for theso ashes, tlic prcftitory notc by lh. L:rndcr states thnt " . . . the conipnrison niay bc considcrecl satisfiictory," and this y)pciirs to I N so because, whcrc defuiitc figures arc givcn, tho grcatcst diffcrencc bct\wen the British and Arncricau figures is 30" C, for fusion tcnipcraturcs. It is php latlicr untortunntc that in cight of tho twcnty detcrininationv tlic Pucl liescnrcli Statioii rcsults wcrc not dcfinitcly stated, but iiicrely indicated n fusion point > 1450" C., \i.ltcrcns the Burcult of JIincs gavo dcfinitc figurcs in d l cases, and in 0110 case ns high as 1605' C.

Tlic rcnson for this appcnrs to be that 1.MY C. is tlic innsiniuni tcmpcrtrturc obtninirblc in the fumnco undcr rcilucing conditions. Tlic f iirniicc opcratcil with an nir prcssurc of (j0-75 lb. 11cr sq. in., nnd its working is fully dcscribcd togcthcr with tiibles nud purticulars of fuwnncc atniosphcro composition. Tliorc nrc also esccllcnt illustrntions of the furiiacc. On page 7 it is stntcd tlint tcnipcriLturcs wcrc mciisiircd by iiieiins of R siiitnblc optical pyrometcr, aiitl 0110 type incntioncd is the (' Fostor hot filnment," but i t may bc prcsiiiiictl t h t tho " Fostor disnppcnring filnnicnt " typo is intondcd.