SCIENCE-ADVERTISEMENTS 



Save Middlemen's Profits on Science Apparatus 



When equipping your ^ 



science laboratory, why pay M 



prices wliich include extravagant traveling expenses and the extra profits of jobbers and dealers, M 



when you can send your orders direct to our factory and in all probability M 



SAVE 25% ON SCIENTIFIC APPARATUS 



p Chapco Laboratory supplies are of the highest grade; 



g in their power to demonstrate scientific laws and principles. 



= sire. Every Chapco article is guaranteed to give satisfaction or 



^ money refunded. Adjustments are always made cheerfully. Shipped 



s in duBt-proof packages bearing our easy-to-check-labels which in- 



^ sure accuracy and facility in checking shipment. No charge for 



= boxing, packing or cartage at this end. 



■ Write for Ch apco Book No. 1 1 state yonr school con- 



^ I I .iTi. ■»■ — ■■ — iMii ■- necbton and get a copy FREE. 



^ It contains a comprehensivelistof artiolesfor laboratory use. Hun- 



^ dredaof articles fully described and pictured. Our prices are the same 



& to all and will be found the lowest possible on high grade apparatus. 



= Chapco Scientific Apparatu ' ' . ^ t,, 



^ trial order to test c 



scientifically accurate and absolutely unfailing ^ 

 In the hands of students they give the results you de- ^ 



Free Book Coupon ' 



CHICAGO APPARATUS CO., 55 S. Clinton St., Chicago 



t Chicago Apparatus Co. 



S 55 S. Clinton Street, Chicago, Illinois 



S Dear Sirs: — Please send your Chapco Book No. 11 to 



2 my address providing I incur no obligation by your 



t compliance with this request. Our school is interested 



I in apparatus checked in the squares below. 



« O Affricultural Apparatus D Physicial Apparatus 



J D Chemical Apparatus £3 Biological Apparatus 



Natural History Material 



ZOOLOQY MINERALOQY 



We have been handling Natural Hiitory 

 Material of all kinds for the past fifty years, 

 and so have aooumnlated a very complete stook. 

 Our pricea are aa low as the quality of the 

 specimens will permit. We ars constantly pre- 

 paring circulars and price lists covering our 

 material in the different branches, which we 

 will bs pleased to send free of charge to the 

 leadeit of Scienee. 



Som* of our reemmt circnltira : 



S-121 Rare Bird Skins 

 S-122 Mounted Bird Skins 

 S-98 Material for Dissection 

 S-123 Pbilippine Land Shells 

 S-120 Special Minerals 

 S-UO Complete TrUobltes 

 S-111 Jurassic Fossils 

 S-119 Cretaceous PossUs 



CONCHOLOGY 



QEOLOQY 



Ward's Natural Science 

 Establishment 



Colleee Ave. Rochester, N. Y. 



Just 'Published 



PRINCIPLES OF 

 STRATIGRAPHY 



BY 



AMADEUS W. GRABAU. S.M..S.D. 



PROFESSOR OF PALAEONTOLOGY IN 

 COLUMBIA UNIVERSITY 



Loige OetaTS. 1150 pages, with 264 Ultutratloni la the t«xt. 

 Cloth bound, prlca, $7.50. 



Send for deiciiptiTe clieular 



A. G. SEILER & CO. 



PUBLISHERS 

 1224 Amrtetdam Avenue NEW YORK. N. Y. 



