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

                                the Morning Twilight, he saw luminous objects, which he 
satisfied himself were stars or the images of stars, near 
the horizon, agitated by certain singular motions which 
he describes, not perhaps with geometrical precision, but 
on the whole in terms clear enough to convey a tolerable 
notion of them. That he <u>did<\u> see such luminous objects 
whether stars or not, so agitated, I implicitly believe, nor 
do I consider it at all certain that they were not stars 
and the phenomenon one of lateral <s>refraction, <\s> compounded 
with vertical temporary mirage*, arising from sheets of 
double-curvature of heated air seen at great distances &
at very oblique angles. (The phenomenon, it will be re-
-membered was seen Eastward i.e. towards the African Coast.)
Such cases where terrestrial objects are concerned, are not 
without example, though rare. A Boat has been seen 
laterally <u>reflected <\u> on the air on the lake of Geneva - Mr 
Fallows saw several bright spots on the edge of the sea-ho 
-rizon, to the right & left of the rising Sun’s <u>expected <\u> place.
Mr. Vince saw the image of Dover Castle transferred from 
the further to the hither side of an intervening hill. A
repetition of refractions through successive lenticular 
masses of heated air, or through successive maxima 
or minima of one continuous mass in motion differently 
presented to the ray in its passage, might produce any 
given amount of lateral, vertical, or mixed displacement 
varying according to any proposed law - without recourse 
to such explanations as those suggested by Mr. Smyth, the 
one of which appears to me inadequate, the other contradictory 
to the phenomenon attempted to be explained.
As cases of 
* I use the term to express terrestrial refraction large enough in 
amount to be seen with the naked eye - not as a doubling of the image