NATURE 



[September 7, 1905 



BOROUGH OF SWINDON. 



EDUCATION COMMITTEE. 



The Committee RKOUIRE the services of an ASSISTANT SCIENCE 

 DEMONSTRATOR in the HIGHER ELEMENTARY SCHOOL. 

 Candidates must be accustomed both to Class Teaching and Laboratory 

 Work. Commencing salary ;£i2o a year, increasing by Ct^ a year to 4i6o. 

 Forms of application, which must be returned by September 15, may be 

 had from 



W. SEATOM, Secretary. 

 Education Omce, Town Hall, Swindon. 

 August 29, 1905. 



MASTERSHIPS VACANT FOR Sep- 

 tember. -Geology, Botany, ZooloRy. Canada, ;£2co. Pas.sage, 

 lioard and 3 Rooms. Chemistry, Physics. Ireland, College, £250. 

 Several Science Graduates, Public College, London University Teach- 

 ing Centre, ^^150 to /300 ; Ditto, Mathematical, j^iso to ;^3oo : Eng- 

 lish, must be in Honors, ;^t50 to C^-js : English and French, ^£150 to 

 ;Cr75 ; 200 Vacancies for Senior, Junior, and Foreign. 



CfEfElTj,T^.A.-Si A. SC CO. 



Send List 10 all Candidates, 

 80 WIGMORE STREET, LONDON, W. 



KING'S COLLEGE, LONDON. 



(UNIVERSITY OF LONDON.) 



The Council invite applications for the post of JUNIOR DEMON- 

 STR-\TOR in ENGINEERING. 



Applications should be sent in by Friday, September 15, 1905. 

 For conditions apply to 



WALTER SMITH, Secretary. 



KING'S COLLEGE. 



(UNIVERSITY OF LONDON.) 



DEMONSTRATOR in ZOOLOGY wanted for October. 1905. Salary, 

 jCrso. For further particulars apply to the Secretary, King's College, 

 Strand, W.C. 



MERCHANT VENTURERS' 

 TECHNICAL COLLEGE, BRISTOL. 



ASSISTANT LECTURER and DEMONSTRATOR in ENGINEER- 

 ING required. Salary, /170, which may rise to ;C220. Particulars 

 obtainable from the Registrar by sending a stamped addressed foolscap 

 envelope. Applications should be sent in not later th.-rn September 18, 1905, 



To SCIENCE and MATHL. MASTERS.— 



REQUIRED immediately for Secondary School near London, Ma-ltr 

 to take Elemfntary Science and Geograp' y. /t5o to commence. Also 

 Malhl. Master for School in W. London. Maths., intluding New 

 Geometry. ilt^o. Many other vac.-incies.— Addre s Grifkiths. 

 Smith, Powell & Smith, Tutorial Agents (Estd. 1833), 34 Bedford 

 Street, Strand, London. 



Wanted for St. Augustine's Seminary, Dun- 



earvan, Co. Waterford, a Te.-icher of Chemistry and Physics. Must be 

 a B.Sc. with honours in Chemi>try. Salary .£140. Non-resident. 

 To take up his duties befcre October 15. 



Newbold Rectory, Stratford-on- Avon. — Home 



School for a limiied number of pupils. Science a speciality. Laboratory 

 and Observatory. Fees moderate. — Apply G. A. S. Atkinson, 

 B.Sc. (Lond.). 



DUBLIN UNIVERSITY. 



SENIOR DEMONSTRATOR of PHYSIOLOGY wantel 

 nencing .salary, ^175. Applic.-.iions to Registrar, Medical School. 



For other Scholastic Advertisements^ see pages cLxxviii, cl.\xi.\' 

 clx.x.\, aiid clxxxi. 



LABORATORY TO LET.— Large well- 



filled Cheinica! Laboratory in neiehbourhood of Hampstead, in be let 

 temporarily. Electric p jwer. Use u' telephone. -^pply Bo.\ 1S71, 

 Ofnce of NATUhE, St. Martin's Street, W.C. 



SCIENTIFIC APPARATUS TRADE.— 



Advertiser, 2fS, experienced and well qualified, de.ires change, — .Apply 

 Bi-x 7r, Nature Office. 



To Science Masters, Curators of Museums, &c 



—Advertiser requires p ist as Assistant. Has knowledge of Geology 

 and Mineralogy.— Apply C. Taylor, 139 Dallin^ Koa I, Kavenscouri 



JAMES SWIFT & SON'S 



NEW PAN-APLANATIC OBJECTIVES 



OF THE HIGHEST POSSIBLE OPTICAL EXCELLENCE. 

 Apochromatics. 



\" N.A.,r.30, oil immersion £8 8 I 



I" ,, 1.40 ,, 10 10 I 



1/12" ,, 1.40 ,, 8 8 1 



Pan-Aplanatics. 



J" oil immersion, N. A., r-30 4 I 



i/io" ,, ,, 1.30 4 1 



t/12" ,, ., 1.30 5 5 1 



Dry Series Pa:i-Aplanatics. 



t" N.A., 0.30 £2 5 I i;. N.A.. o.So 1 16 



J" „ 0.50 2 J" „ O.S3 2 17 



S" ,, 0-30 1 4 I I" ,, 0,92 2 



|)«- Nature says:— "In the excellcnc 

 oil immersion, they have produced : 

 capacity which is a marvel of cheapness," 



LISTS POST FREE ON APPLICATION. 



of their i/i2-in. 

 t English-made le 



81 



UNIVERSITY OPTICAL -WORKS. 



Tottenham Court Road, London. 



SCINTILLOSCOPE 



(PatkntJ. 

 Shows a magnificent display ot scintillations, 

 showers of sparks, direct from the mineral Pitch- 

 blende, Radium, Polonium, Uranium, Thorium, or 

 any radio-active substance, even a Welshach mantle 

 contains sufficient Thorium to excite the very sensi- 

 lue screen of the Scintillnscope, which is far mors 



sensitive than the Spinthariscope. The Scintil- 

 loscope rivals the most delicate Electroscope as a 

 deiector of Alpha rays. 



The eye sees an inexhaustible shower of stars of 

 white light, giving a very realistic idea of the cease- 

 less activity of these marvellou.s substances which 

 ific bombardment causing this beautiful display. 

 i*" See Nature, September 29, page 535. 

 Glew's Sclniilloscope Superior Lens, with Extra-sensitive Pitchb'ende and 

 Polonium Screens, giving brilliant effects, Complete, ■]$. 6</. , Post free, 

 U.K. Foreign Postage exln, weight 2 ounces. 

 Pieces of Pitchblende mineral, ground flat and polished, with Sensitive 

 Screen attached, for use in Scintilloscope or with any strong pocket 

 magnifier, from 7.1. Sd. each, according to size- 

 Radio-active supplies of every description, on Sale or Hire. Radium 



Bromide 1.800,000 units on hire for lectures. 

 F. HARRISON GLEW, Radiographer (Silver Medallist, Paris, 1900), 

 156 Clapham Road, London, S.W, 



: producing th 



Camera Stand through 

 graphy and found it an excellent 

 every conceivable difficulty of 

 great boon. 



Wishing it and those who us 



WM. BUTLER, Esq 



BUTLER'S 



"SWINCCAM"^ STAND. 



A SPECIALITY IN TRIPODS. 



TESTIMONIAL 

 from Mr. R. KEARTON, F.Z.S. 



Caterham Valley. Surrey. August 4th, 1905. 

 ire in stating that I have put your new " Swingcam " 



Bird-photographers will find I 



WHITE FOR PAMPHLET AND PRESS COMMENTS. 



WM. BUTLER, 20 Crosby Road, Southport. 



RARE 



CHEMICALS 



METALS 

 MINERALS 



For Laboratory, Scientific, and all otlier 

 purposes. 



RADIUM SALTS & RADIO-ACTIVE PREPARATIONS. 

 CALCIUM METAL, 1/6 oz. ; 20,- lb. 



"Price List on Application. 



HARRINGTON BROS., 



4 OLIVER'S YARD, CITY ROAD, LONDON, F.C. 



