J*<r-s(niill <lii<l Set, iifip'c ?^<irK. 4-OH 
Part VIII, June, liStH, coutaius: The Coustruction of Telescopic Object 
♦ilasses for the International Photographic Survey of the Heavens, by 
H. Grubb. 
Eleventh Annual Iteport of the Department of Mines of New Soutli 
Wales, for the j^ear 1890. 
PERSONAL ANJ) SCIKNTJKJC NKWS. 
(tRani> Falls. Labrador.— Mes.srs. Kemistoii and IWyant. 
the explorei's who ciuite reccMitly retitrnod from a trij) to Lal)ra(lor 
announce sonic accurate measurements taken at Urand l''alls. 'i'hc 
tall isj>l(> feet, or if the rapids l»e incUuled the descent would he 
500 feet. The width is 200 feet; l»ut on u'oiny' back half a mile 
the river is from ]2(M» to ir)<>0 feet wide, liradually narrowinjr un- 
til it reaches the falls j)reoipice. After passin<r over the preci- 
pice the river runs for a distance of twenty-iive to thirty miles 
through a narrow canon, tlu' walls of whicli rise to a liight of 
from 300 to 400 feet. 
SiLVKR PuonrcTroN. — Dr. A. K. AVendl is of the opinion that 
in)twithstanding all authorities to the contrary, the a gg legate pro- 
duction of the Potosi silver mines of l>«»livia lia> not r\cee<l('d 
1.000.000.000 ounces. 
It is ixH'HTKiM, IK ANV A.MKRICAN K.\ I'KOiTioN of rcccut years 
has heeu so fruitful of good results as that uinU'rtaken recently 
l»y Messrs. Mc(Jee, Ward, and Hill into the southern coastal re 
gions of Mississippi, Tennessee, liouisiana. Texas, and Mexico: 
the party has returned to Washington with a most valuable col- 
lection of data. Tn Teiuiessee. Mississippi, and iionisinna they 
were accompanied by professors Satford. of 'J'ennesst'c. llilgard. 
of California. Smith, of .Vlabama. and Holmes, of Xortli Caro- 
lina, who visited all tlu' historic localities, and in the Meld dis- 
cussed and bannoni/.ed opinions, and devised metho<ls that will 
soon n'sult in a clear elucidation of the Neocene features of the 
Atlantic and (Julf slope. 
Messrs. .Mcdlee. Ward, and Hill contiiuu'd ihi' work in Texas 
and ^lexieo. and obtained a vast store of information concerning 
the geographical, geological, and botanical I'i'lations of those re 
gions of the rnited States. '{'he renuirkalilc orograi)hic develop 
ment of northeastern .^lexico was I'econnoiti'etl. and the interest 
ing Jurassic and Comanche beds visitecl. pioving lieyond douitt 
tliegi'cat developnu'nt of the liowci' Ci'ctaceous in that country. 
Finally the 'I'linity l>eds of Tt'xas. a great formation hithert(» lit- 
I li" a|)pr('ciale(l. were visited liy Profs. Ward and Hill, it-sulting 
