XV 
Dr. BARHAM also exhibited and remarked on diagrams* 
showing the very considerable difference between the temperature 
marked by means of instruments placed on grass or but a few 
inches above ground, and those placed at the usual elevation of 
about 5 feet. Mr. R. W. Fox had furnished him with results of 
observations at Penjerrick, at a height of about 200 feet above 
the sea, the Observatory at Falmouth being only about 100 feet ; 
and observations had also been kindly forwarded from Helston 
by Mr. Moyle, and from Bodmin by Captain Liddell. One of 
the Tables gave daily observations for the month of April last, 
when the weather was dry with a clear sky, well calculated to 
bring out the differences of temperature between the air “at grass” 
and that at a higher elevation. The other diagram represented 
the monthly means and extremes for the year 1872. It was 
important to remark the very great differences between Falmouth 
and Penjerrick even in April; in one instance no less than 18 
degrees, and there were several instances of such differences as 
15, 12, and 10 degrees; and very similar results were observed 
at Bodmin and Helston. The practical importance of all this was 
very great indeed, because it was the temperature at grass that 
affected vegetation ; so that while at Falmouth Observatory the 
recorded temperature was 48°, a very safe temperature for 
vegetables, at Penjerrick, on the grass, it was as low as 30°—a 
coldness which might be destructive of vegetation. In one 
instance, in 1872, the surface temperature at Penjerrick was as 
low as 18°,—14 below zero, at a time when at this Institution the 
temperature was 26°. It was of very great importance that a ~ 
knowledge of such facts should be widely diffused, in order that 
contrivances might be employed to counteract the injurious effects 
of extreme cold. The main object to be aimed at was to prevent 
radiation of heat from the earth’s surface. 
A letter, dated 14th May, 1873, from Mr. N. HARE, junr., 
Liskeard, an Associate of the Institution, recorded the following 
Ornithological incidents in the vicinity of that town: 
‘‘T have just been shown a Ruff (Machetes pugnax) which was shot last 
March, whilst feeding in a marsh at Tremabe in this parish. Though 
plentiful in the great fens of the Midland Counties, the Ruff appears to be 
of rare occurrence with us. The Game-dealer to whom it was brought, and 
who has been in the business all his life-time, told me that he had never seen 
one before. He was informed that the bird was a Sandpiper; but its yellow 
legs led him to think otherwise, and he sent it to a bird-stuffer to be mounted. 
The plumage of this specimen is of a lighter colour than usual, and the 
spots on the breast are few and indistinct ; indicating, perhaps, a bird of last 
season. 
* See Diagrams at the end of Jowrnal, No. XY. 
