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

                                on the construction & packing of the Instruments used - The 
woodwork seems to have shrunk (a sufficient reason for the 
avoidance of hygrometrical materials in their framework & scales 
in future), the fluid to have leaked, & the interior thermometers 
to have been broken in the transport. As the fluid is one perfectly definite 
& may be carried in a bottle, or manufactured at an hour’s 
notice & at almost no expense & a stock ought always to be sent with the instrument 
which need not be filled till it arrives at its point of des-
-tination (the work of a moment.) - as the handle of the interior 
thermometer is made to unscrew & take out, & may, with its 
thermometer be packed in cotton of any degree of puffiness, and 
lastly as (with a view to prevent the long thin thermomr. from 
breaking by a shock when filled with Mercury,) it was expressly 
recommended that it should not be a mercurial one, it is 
obvious that all these causes of failure are within easy control,
and I now refer to them not as casting blame, but as indicating 
the precautions to be taken by future travellers in similar circumstances. Another ground of 
complaint was the crystallization of some copper salt in one case 
& the discoloration of the liquid in another (probably by <s>the <\s> contact with brass) The remedy is 
obvious. [text?] to do as is recommended in my instructions for 
the use of the instrument in the Admiralty Scientific Manual 
p. 289., to wash out the chamber with diluted acid, and 
rinse, and refill it with fresh liquid. - 
Mr. Smyth further objects against the Actinometer that the 
length of time requisite to make a series of 5 Sun & 4 Shade 
observations as recommended in the Admiralty Manual, is too 
great <u>long<\u> to allow rapid fluctuation in the effective radiation to 
be perceived - but it is obvious on the smallest consideration 
that the question is one of mere grouping & that a continuous 
series (my own practice has always been to make such) may be 
broken up in<s>to<\s> reducing, into groupes of (5,4), (3,2), (2,1), or (2,1) & (1,2)
alternately <u>ad libitum <\u> - and that if for special occasions, ex-