SCIENCE 



A WEEKLY RECORD OF SCIENTIFIC PROGRESS. 



ILLUSTRATED. 



Entered in the Office of the Librarian of Congress, at Washington, D. C. 



No. 52-Vol. II. 



June 25, 1 881 



Price lO Cents. 



The "Acme" Microscopes. 



"Acme " No. 2. 



Monocular, . . $ioo 

 Binocular, . . . 145 



"Acme," No. 3. 



Monocular, . . . $50 

 Binocilar, ... 75 



" Acme" No. 4. 



The favorite Laboratory 

 Stand, ... $25 



With 1 inch and )i inch 

 objectives, . . 50 



Special Terms made with 

 Colleges. 



pHSlLUUlh 



"Acme" Lithological. 



A new Stand, after the pat 

 tern of the No. 3, for the study 

 of Rocks ; convertible in an 

 instant into an ordinary mon 

 ocular. $Q2 



All our Stands 



have same size of tubing ana 

 sub-stage fitting, so that eye. 

 pieces and accessories that fit 

 one Stand can be used with 

 a. 



Congress" Turr Table 

 Patented, $6.50. 



Gem Turn-Table, $2.50 



Do. Do. with improved 

 centering adjustment, $3.25 



•ACME" No. 3. 



HOLMAN'S COMPRESSOR, THE LATEST AND THE BEST, $4. MECHANICAL FINGER, $5. 

 JOHN W. SIDLE & CO., Lancaster, Pa. 



Send for Catalogue. 



