THE SECRETARIES* REPORT. 
175 
these are valuable, and many are polished. Looking at the present 
state of geological science, and the fact that recently the new 
science of Petrology has been developed by the aid of the micro- 
scope, as that of Mineralogy was also long since propagated, it has 
been thought desirable to place these by themselves as a nucleus of 
the distinct branch of Petrology, and this has consequently been 
done. Several additions have already been made, among which may 
be mentioned a series of polished Devonshire marbles by Mr. J. 
Goad, and a series of rocks, from the neighbourhood of Cawsand 
Bay and other places in the locality, by Mr. Worth. The Borough 
Surveyor has also arranged to reserve samples of all the trap rocks 
received from the various trap quarries of the neighbourhood. 
Specimens of granites, &c, have likewise been promised. This 
department therefore bids fair to become one of very considerable 
importance. Hence it is that a proposition will be submitted to 
the Annual Meeting to appoint an independent Curator to this 
department, as has already been done in the case of Mineralogy. 
The space occupied by this collection in the northern Gallery is 
fitly placed in juxtaposition to the mineralogical cases. 
"The economical necessity for such a collection as that now 
indicated may be seen in the difficulty recently experienced in the 
selection of suitable stones for the erection of Truro Cathedral ; 
and, to refer to another case nearer home, it may appear incredible 
that the officials of the Works Department of the Home Office 
were actually ignorant of the existence in this locality of any 
building stones suitable for such a building as that now being 
erected in Westwell Street for the new Post-Office ! This accounts 
for its being built of brick and Bath stone. In fact we are having 
a London building transplanted to Plymouth." 
The Curator of the Library reports : 
" Beyond the matters yearly requiring mention in connection with 
the Library of the Plymouth Institution there is little to report at 
the present time. Many volumes of serials have been bound, parts 
of 'Transactions' and 'Eeports' of other learned and scientific 
societies received, and some purchases made for the library. A 
short time ago it was found impossible to arrange all the volumes 
on the shelves for want of space, and a resolution of the Council 
authorised the sale of the ' Delphin Classics ' set, by the disposal of 
