84 



NEGRETTI AND ZAMBRA, HOLBORN VIADUCT, F.C., 



FlQ. 96. 



FIG. 97. 



turned in a lathe, and terminated at its lower extremity in a bent tube of 

 small aperture, in which the last few drops of rain remain as shown in the 

 engraving. The glass receiving vessel is graduated to hundred ths of inches 

 according to the calculated weight of water, as determined by the area of the 

 receiving surface. In use, the gauge is partly sunk below the surface of the 

 soil, so that the receiving surface is about eight inches above it. Thus situated, 

 no water escapes by evaporation in any month of the year. If placed 

 differently, the readings must be taken daily. 



Price t in Japanned Tin . 1 1 



in Copper . . 1 10 



RECEIVING VESSEL FOE GLAISHER'S GAUGE. Price, in Japanned Tin or Copper, 2s. <k 3s. 6d. 



As some meteorologists have objected that the curved tube at the base of 

 the funnel is liable to be choked up with dust, Messrs. Negretti and Zambra, if 

 desired, supply these Rain Gauges with a straight tube of sufficient length to 

 reach very nearly the bottom of the receiving vessel, thus obviating this diffi- 

 culty, and at the same time preventing evaporation. 



111. Glashier's Rain Gauge, with extra large receiving vessel, mounted 

 with a convenient tap for drawing off the water, suited for Tropical countries 

 or stations where there is an excessive rainfall. Price, in Copper, 330 



The 8-inch Glaisher's and the Meteorological office Rain Gauges are now 

 considered by scientific men the best, and consequently are almost universally 

 adopted as Standard instruments, but at the same time we would observe that 

 most valuable results have been obtained by the use of Mr. Symons' 5-inch 

 gauge in many parts of the United Kingdom. 



