208 BURTON E. LIVINGSTON 



tained by measuring the amount of water removed from the 

 reservoir which may have any convenient form. 



It may be added that the new porous cones may be employed 

 in atmometry, hke Bellani plates, by water-proofing the cylin- 

 drical and conical portions of the exterior and grinding the cir- 

 cular base to a plane porous surface. For water-proofing this 

 porous ware (which it is difficult to glaze in a satisfactory manner), 

 Valentine's "Valspar" varnish, perhaps diluted a little with 

 benzene, is found to be very satisfactory, better than alcoholic 

 solution of gum shellac. Wherever a circular porous clay plate 

 with a water container behind it is needed, these cones, or the 

 Bellani plates just mentioned, may be of use. 



