Referee report by J. F. W. Herschel on 'Astronomical Experiment on the Peak of Teneriffe, Carried out under the Sanction of the Lords Commissioners of the Admiralty' by C. Piazzi Smyth

                                exposures of 60s be considered too long, nothing prevents them 
being curtailed to 30 or 20. *[Insert here] * Or the rising and falling columns, while still allowed to go 
on rising or falling for 60s may be read in the act of so doing 
at the intermediate 20s or 30s without interfering with a 
systematic adherence to the normal interval. -
The Council will, I hope 
excuse these remarks which I may not have another opportunity 
to make elsewhere - I wish to rescue at least in their [text?]
an instrument which I believe to be really perfect in principle 
and (if well made which I strongly suspect Mr Smyth’s was not)
quite free from all the inconveniences complained of,
from imputations which may lead meteorologists to 
discard it from use. -
However Mr Smyth has recorded facts enough to prove most 
distinctly the very large percentage of extinction of solar heat 
in passing through the lower air - The immense force of solar 
radiation at the Alta Vista is far more than can be reasonably 
accounted for by the dust-haze. -
I come now to a subject (that of lateral refraction) the 
treatment of which I would earnestly recommend to the 
Author’s reconsideration, as it appears to me calculated 
to give great pain to one, whom every lover of science would 
wish to treat & see treated in his feeble and declining years 
with all possible deference and regard. - Even in a case 
in which it should appear that some of the concomitant 
circumstances, which he has recorded as adjuncts of an 
observation in itself curious and almost unique, should 
be found incapable of verification & must be inferred to 
have originated in mistake, haste or inadvertence. Baron 
Humboldt relates from the ice cavern on Teneriffe, in
the