ENC 



Friday, October 5, 1900. 



Single Copies, 15 CTS. 

 Annual Subscription, $5.00. 



. GAERTNER & GO. 



Astronomical and 

 Physical Apparatus 



5347 AND 5349 LAKE AVE., CHICAGO 



SPECIALT/ES 



Standard Apparatus of New and improved Designs 

 READING Microscopes and Telescopes 



AstronomicalTelescopes Dividing Engines, 

 comparators 

 General Laboratory Ap- 



Spectroscopes 

 mlch^lson interferome 



TERS 



Bolometers 

 Heliostats 



PARATUS 



IVERSAL Laboratory 

 Supports 



MODELS ILLUSTRATING PHYSICAL GEOLOGY 



We are issuing the aeries of 25 plaster models in relief, prepared by Profs. N. S. Shaler, VVm. M. Davis and Dr. T. W. 

 Harris for use in Harvard University classes, and 20 photographs used in the same institution in connection witia them. 

 Each model and photograph is accompanied by full explanatory label prepared by Prof. Shaler. 



The series is the moat important aid to the teaching of either Geology or Physiography that has ever been offered to 

 teachers. It is adapted equally to College or High School work. Write for illustrated descriptive circular. 



WARD'S NATURAL SCIENCE ESTABLISHMENT, 30 to 40 College Ave., Rochester, N.Y. 

 STAR-NAMES AND THEIR MEANINGS, 



by Richard Hinckley Allen, has recently been issued. This is a liandsome octavo volume containing 20 pages 

 of Introduction, 485 of Text, with 74 of Indices and List of Authors and Authorities. 



It is the first extensive work of its kind since the publication of Meier's Stern-Namen in 1809. The book 

 is printed in the best style of the De Vinne Press. Price in cloth, with gilt top, $5.00 net. 



G. E. STECHERT, 9 East 16tli Street, New York. 



Scientific Apparatus 



ELECTRICAL ENGINEERI NG and 



PHYSICAL LABORATORIES 



If you have not already received a copy, write for Catalogue B 

 (2d edition) " Electrical Measuring Instruments." Contains over 

 120 pages, well illustrated. Issued June, 1900. 



A Specialty of "Duty Free" Importations from Socii^ti Gene- 

 voise and other promiueut European makers, 



James G. Biddle 



1034 Drexel Building PHILADELPHIA 





