Agricultural and Forest Meteorology. 
61 
The Meteorological Council, in their Weekly Weather Report, 
give means for weekly periods, but for larf^o districts of country, 
so that, while these meet the demand of the Conference in one 
respect, they fail to do so in another — the giving of local details, 
except in the immediate vicinity of the stations. 
K. 5. "It is recoramunded that comparative experiments should be con- 
ducted on tlic best modes of thermometer exposure. (A description of the 
modes of exposure adopted in different countries will be forwarded to the 
members of the Conference, as soon as the necessary particulars liave been 
collected.) " 
The subject ot the best mode of thermometric exposure is one 
of those about which there exists at present the greatest differ- 
ence of opinion amongst meteorologists, and it has been re- 
peatedly proposed to publish such a general conspectus of the 
existing practices as to thermometer observations, but as yet the 
work has not been done. The method all but universally 
employed by the meteorological societies in the United King- 
dom is to suspend the thermometers four feet above a grassplot, 
in a louvred wooden case like a small meat-safe — the screen 
devised by Mr. Thos. Stevenson, and named after him. This 
screen is intended to prevent any direct heat from the sun or 
radiation from the earth, &c., warming the thermometers, and 
on the other hand to cut off all radiation from the thermometers 
to surrounding objects. In the Glaisher screen, formerly much 
used at British stations, the thermometers were too freely exposed 
to the sky on the side away from the sun, and were therefore 
much affected by radiation. 
The idea was, however, broached at the Conference that ther- 
mometers destined to give information for agricultural purposes 
should be freely exposed without any screen at all, inasmuch as 
plants can have no artificial protection against radiation. The 
President of the Conference, the Chevalier Lorenz von Liburnau, 
exhibited such an arrangement, and another came from Italy, de- 
vised by Professor Bellani, under the name of the Meteorological 
Mast, which is to be rigged up with the various instruments. 
The idea has occasionally been tried in this country. At 
Yester House, Haddington, the Marquis of Tweeddale had for 
many years a set of self-recording instruments freely exposed to 
sun and rain in the middle of a large field. At Crowborough 
Beacon also, in Kent, Mr. C. L. Prince has made trial of a plan 
apparently similar to Prof. Bellani's, but no results have as yet 
been published. 
E. 6. " As regards the hours for daily observation, the Conference is of 
opinion that when two observations only can be taken, it is preferable to take 
these in the morning and evening, with the indispensable addition of observa- 
tions of maximum and minimum temperatures." 
