176 Till Ann rl<-'i/i (iiiiliKJisf. September, 1891 
Niix.m trititinUi Say, Jour. Phila. Ao. Xat. Sci., (1) ii, 1822, p. 231. 
" " Conrad, Il)itl, vi, 1830, p. 211 ^^Nnsitit peralta. 
'* •' Mort., Syuop. Org. Kern. Crct. Gp., 1834, App., p. a 
=Xris>ifi peralta. 
Burr I It urn tricittoima Con., 2d Bull. Proc. Nat. Inst., 18-12, p. 186 
NuKHii peralta. 
" " T. & H., Plioc. Foss. S. C, 1857, p. 135=iV^ trivittata 
Tritia {ya»»,i) tririttnin f Con., Proc. Ph. A. X. S., 1862, p. 563 
\ Naxi^a peralta & 
] N. tricittata. 
Tritia trivittata Meek Check List 1864, p. 20 ^^S ^J"""' peralta & 
I J\. tricittata. 
Pti/rhosalpin.r (Tritiaria) peralta Con. Ain. Jr. Con , 1867, p. 264, pi. 19, 
tig. 5. 
-., . • ... ^ TT -1 T. t /^t 1 iou( (58,61^ Na»ii<i peralta d- 
:^asKa trivittata Heilp., Tert. Geol., 1884, pp. j _-^' ^ j^r fy{fiftni,i 
" " Proc. Phila., A. N. S., 1887 pp. 398,' 401 .... . 
^ ?i\r. tririttatoides. 
Nax)<a {Tritiaria) trivittata Clark, .1. II. Univ. Cir., 1888, p. 66 --^N. peralta. 
Nanxa trivittata Clark, Ibid., 1891, p. 107 ^^X peralta. 
Washino;ton, D. CxVugust, ISOl. 
EDTTOPJAL COMMEXT. 
DlMINlTIOX OK NaTL'HAI. GaS. 
Prof. J. p. Lesley has contributeil a paper <»f much interest aiul 
vahie to the i)roc'eeclings of the American Philosophical Society 
on the Grapeville gas wells. From it we condense the following: 
A taV)le showing the futility of all attempts to pipe natural gas 
to any great distance is a sufficient answer to the hopeful tone 
so often assumed in regard to its conveyance to towns far from 
the wells. It shows the initial pressure, size of pipe and loss l»y 
friction in conve3-ing gas from the powerful gusher at Grapeville 
to the Cambria Iron Works at Johnstown. Pa. 
Distance from 
Size of 
well. 
pipe. 

10 
4 
it 
8 
(( 
12 
" 
16 
(i 
20 
(t 
24 
12 
28 
t( 
32 
16 
36 
tt 
40 
20 
18fe6 1887 
Nov. 13 Mar. 15 
Loss. 
200 lbs. 333 lbs. — 
182 " 320 " 13 
170 " 295 " 25 
148 " 261 " 34 
129 " 212 " 49 
100 " 168 " 44 
85 " 130 " 38* 
70 " 95 " 35 
58 " 76 " 19 
51 " 37 " 39 
25 " 12 
The diminution of pressure in 40 miles from 200 ll)s. and 3:>:^> 
