■842 A^/)-iri(Jh(ra( Journal of Victoria. 



HOW TO FORETELL FROSTS. 



Btj G. H. Adcoch, F.L.8. 



During the piesent winter there liave been nujnerous enquiries 

 regarding the means of turetelling frosts, and thus being prepared to 

 avert the injury attributable to this cause. It has, tlieiefore, been 

 deemed advisaltle to give a short account of tlie method in tlie 

 Journal of Agriculture, and to fuinish a D'^w-point 'lal>le, so that by 

 being jtrepared, vignerons and otliers nia}' be able to save tiiemselves 

 the serious hjsses of wliich frosts have so often been the cause. 



In the Journal of Agriculture, vohime i., page 877, Mr. Dubois 

 gave concise instructions for the procedure to protect tlie young, 

 tender slioots of vines ami other plants (such as potatoes, etc), from 

 injury, by laising a pall of smoke over tlie vineyard before sunrise, 

 and thus j)reventing the too rapid thaw, wliich is often so fatal to 

 tender growth. This method of protecting the vineyard is, 1 lielieve, 

 thorouijjhly understooil ; and is, as a matter of fact, widely practised 

 througiiout this State. Mfiny vignerons, from actual expeiience, can 

 testify to the benefit of this plan. 



But the difficulty has always been to know, with anything like 

 certainty, when it would be necessary to light these fires. 



The Jules Richard Frost-regi.stering Thermometer, described by 

 Mr. Dubois in the article just quoted, gives warning by means of an 

 electric bell, which rings when the temperatuie falls to a certain 

 point to which the instrument may be set. The manager is roused 

 by the alarm, and loses no time in calling suffici*'nt assistance to light 

 the fires, and thus protect the young shotits with smoke. 



This instrument has been used in Victoria, and 1 venture to 

 predict will be moie extensive!}' adopted when it becoujes better 

 known. 



The method of predicting frost by means of the dry and wet bulb 

 thermometvic readings and a dew-point table is by no means new, 

 and has been adopted with great success in many parts. Mr. 

 F. de Castella, of Chftteau Dookie, may fairly claim to be the pioneer 

 of this system in Victoria. 



The therujometers used for the purpose should be reliable and 

 identical instiuments, provided with small bulbs, and fixed at least 

 4 inches apart. They should not be placed where their temperature 

 is raised by radiation of heat from buildings, etc. 



The wet bulb, as the name indicates, is kept moist. This is 

 usually managed by putting round it a piece of some thin fabric, such 

 as muslin. A strip of this material, or some attached threatis, coui- 

 municate with water in a vessel proviiled for the purpose. The 

 covering of the wet bulb is kept constantly moist by capillary 



