III. SPECIAL THERMOMETERS. 689 



2827J. Negretti and Zambra's Thermometer for the 

 determination of Terrestrial Radiation. 



Negretti and Zambra. 



The bulb of this instrument is transparent with divisions engraved on its 

 stem. In use, to be placed with the bulb fully exposed to the sky, resting on 

 grass with its stem supported by forks of wood. The divisions and figures are 

 protected by an outer glass tube. 



2826o. Original Self-registering Maximum Thermo- 

 meter. Made by Prof. Phillips. ' Hicks. 



Metallic Thermometer, Maximum and Minimum. By 



Hermann and Pfister, of Berne. JR. II. Scott, F.R.8. 



Wet and Dry Bulb Hygrometer. Same principle as that 

 used with the thermometer No. 2827e. Negretti and Zambra. 



Large Six's Self-registering Thermometer, with black 

 scale on transparent glass. Pastorelli. 



Small Six's Self-registering Thermometer, with two 

 arms to tube. Pastorelli. 



Delicate Thermometer, with gridiron bulb. The only 

 instrument of the kind ever constructed. Negretti and Zambra. 



Standard Meteorological Thermometer, with elongated 

 bulb. Casella. 



Standard Thermometer, with elongated bulb. 



Elliott Bros. 



Portable Wet and Dry Bulb Thermometers (hygro- 

 meter), with elongated bulbs, on brass stand. Pastorelli. 



Small Portable Wet and Dry Bulb Thermometers 



(hygrometer), on black scale, with white figures and graduations, 

 mounted on its own case. Pastorelli. 



Wet and Dry Bulb Thermometers (hygrometer), with 

 maximum and minimum thermometers, on one support. 



S. G. Denton. 



Wet and Dry Bulb Thermometers (hygrometer). 



J. Hicks. 



Wet and Dry Bulb Thermometers (hygrometer). 



Negretti and Zambra. 



Wet and Dry Bulb Thermometers (hygrometer), with 

 elongated bulbs. Casella. 



40075. X x 



