i88ij 
Notes. 
247 
The Rev. C. W. Dod, writing in the “Journal of the Society of 
Arts,” says : — “ I may add that a heavy plant-label is not alto- 
gether without its advantages. In the year 1842, when I was a 
boy at Eton, one of the many jackdaws which built in the 
College Chapel insisted upon having her nest so arranged that 
she could, whilst sitting, see out of the turret loophole, which 
looked towards Windsor Castle. This could only be done by 
making the foundation on a step of the spiral staircase, 9 feet 
below ; and a massive nest, 9 feet high, was accordingly built. I 
made friends with the college clerk, and watched the progress of 
the nest, and recolleCt that amongst the materials, besides there 
being a box of lucifer-matches, garden-pegs seemed to be in 
great request. Three or four years later, when I was at Cam- 
bridge, I recolleCt the present Professor of Botany exhibiting, at 
a meeting of the Ray Club, a newly-devised label for use in the 
Botanic Garden there. It was a very heavy metal one — the 
weight, he said, being found necessary to prevent the jackdaws 
carrying them up for their nests between the roofs of King’s 
College Chapel.” 
M. Ch. Fievez (“ Comptes Rendus ”) considers that if, of two 
heavenly bodies, the one presents broader and more nebulous 
hydrogen rays than those of the other, the former possesses the 
higher temperature. 
According to M. G. Rolland (“ Comptes Rendus ”) a tempera- 
ture of -4*7° C. was experienced in the Sahara in the night 
between the 17th and 18th of January, 1880, the latitude being 
35 ° N. 
M. G. Rolland, in a paper read before the Academy of Sciences, 
considers it evident that the climate of North Africa, has become 
more arid since the Roman epoch, and that the Sahara in parti- 
cular has deteriorated within traditional ages. This agrees with 
the remark of the Rev. Canon Tristram, that the fauna of the 
Sahara has a less decided desert character than that of Arabia. 
Mr. F. H. Wenham, in a communication to Mr. J. Mayall, jun* 
(“Journ. Royal Micr. Soc., 1881, p. 121), gives, among other 
information, a method of setting the front lens of oil immersion 
objectives. The usual mode of “ burnishing in ” is difficult and 
uncertain, and to make an oil-tight fit the hard metal must bear 
heavily on the fragile glass, with the liability of distorting its 
figure. The following plan is recommended : — The cell is to be 
turned clear out, so that the lens would drop easily through. 
The cell is then heated, and a conical-pointed copper-wire, well 
tinned, and a fragment of rosin for a flux, is twisted round until 
a ring of tin is formed round the hole. The tin lining is then 
turned out true, to form the cell and bed for the lens, leaving the 
projecting ring necessary for burnishing. This operation is per- 
formed with an ivory stylet lubricated with soap. Before the 
