JAN 20 JCQ5 



SCIENCE 



New Series 

 Vol. XXI. No. 526. 



i2 6. ^IqIj^ jFriday, January 27, 190 5. 



Single Copies, 1.5 Cts. 

 Annual Subscription, $5.00. 



Students' Spectrometer 



**R First*eiass Instrument at a Moderate Price." 



This instrument has a protected 5-inch circle, reading by two oppositely set verniers 

 to one minute, with clamp and fine adjustment to both telescope and prism table. The 

 prism table can be raised or lowered, and is adjustable by means of three levelling 

 screws. The telescope has rack- motion focusing arrangement, and is fitted with cross 

 wires. The collimator is provided with an adjustable slit. A grating holder, a prism 

 clamp, a magnifier for reading the vernier, and a neat wooden carrying case are supplied 

 with the instrument. 



This spectrometer can be shipped from stock, or imported duty free for schools and 

 •colleges, at the following net prices : 



S*I8. Students' Spectrometer . . . 



S-19. Dense Flint Glass Prism . . 



S*20. Hollow Prism for Liquids . . 



S«21. Replica of Rowland Grating 



Sf23. Gollimating Attachment to Eyepiece 1.75 



Duty Free 

 $38.00 

 3.50 

 3.75 



Prom Stock 

 $55.00 

 5.10 

 5.45 

 5.00 

 2.55 



THE SeiENTIFie SHOP 



ALBERT B. P0RTER 



Scientific Instruments 



322 Dearborn St., GHieAGO 



