CEXTEAL SCIENTIFIC CO., CHICAGO, U. S. A. 



493 



No. 13514. 



Nos. 13518-9. Nos. 13518-9. 



No. 13522. 



13507. THERMOMETER TUBES, extra, for No. 13506. 



Xo A B 



Each..... $3.30 3.30 



No 13508 13508. THERMOMETER, Automatic Alarm, for giving an alarm the instant the tem- 



perature registers a given degree. Consists of a straight mercury tube, into 

 the bore of which a fine platinum wire is fused at 32 F., or at any other 

 degree desired. Through a non-sparking relay attachment a bell is made 

 to ring at practically any distance from the thermometer itself, at the exact 

 moment the temperature where the instrument is located reaches the danger point. Strongly 

 constructed and fully protected by a heavy metal weather-proof case, which allows circulation 

 of air. May be installed in three different ways: (1) one thermometer and simple alarm; 

 (2) more than one thermometer and simple alarm; (3) more than one thermometer and an- 

 nunciator alarm showing exact location of danger point. In ordering, kindly state the tem- 

 perature at which alarm is to be given. Complete with relay, but without batteries, bell, or 



wire 18.00 



13510. THERMOMETER, Automatic Alarm, similar to No. 13508, but arranged to ring at either of two 

 temperatures desired, which must be specified when ordering. Complete with relay, but with- 

 out batteries, bell, or wire 24.30 



13514. THERMOMETER, Bake Oven, Medium Grade, consisting of a glass tube, mercury-filled, mounted 

 on 5-inch flanged metal scale with sand blast finish and white figures. With round removable 



base with asbestos mat attached. Range, about 100 to 600 F 1.50 



THERMOMETER, Beckmann, for the exact determination of slight changes in temperature. 

 Widely used in calorimetry and in boiling and freezing point determinations. Consists of a 

 capillary of normal glass graduated to 1/100 degree over a range of 5 or 6 C., with an 

 auxiliary scale at the top graduated from -10 to 120 C., in 2 divisions, sealed in a glass 

 jacket with metal cap. The thermometer may be set to read at any temperature between -10 

 and 120 C. Constructed and graduated according to the requirements of the United States 

 Bureau of Standards. 



13518. Without certificate 20.00 



13519. With Bureau of Standards certificate 32.50 



THERMOMETER, Beckmann, improved, similar to Xo. 13518, but with improved method of ad- 

 justment of temperature. In the reservoir beneath the auxiliary scale is a short capillary (a), 

 the opening of which is adjusted to deliver a drop of mercury of sufficient size to produce a 

 fixed change of temperature in degrees C., the exact amount of this change being engraved on 

 the scale of the thermometer. This improved construction obviates the necessity of tapping 

 the mercury column, with the consequent danger of breakage. It also makes easier the return 

 of excess mercury from the reservoir to the bulb which takes place automatically if the ther- 

 mometer is held in a perpendicular position. Mercury from the reservoir may be transferred 

 to the side arms by merely inclining the thermometer. Graduated according to the require- 

 ments of the United States Bureau of Standards. 



13-.22. Without certificate 25.00 



13523. With Bureau of Standards certificate 37.50. 



