160 ORIGIN OF ROCK PRESSURE OF NATURAL GAS. 
stand or fall. In the accompanying table I have indicated the follow- 
ing lines of facts as to strictly representative wells in the leading dis- 
tricts of the new gas fields, viz, (1) location, (2) depth at which gas is 
found, (3) relation of this depth to sea level, (4) the initial rock pres- 
sure of the gas. In regard to the last line of facts I have taken, in 
almost all cases, figures that I have myself verified. (5) A fifth column 
I add, in which the pressure due in the particular well is calculated 
from the two following elements, viz, an assumed elevation of the salt 
water to the Lake Superior level, or 600 feet above tide; and, secondly, 
an assumed specific gravity of the salt water of the Trenton of 1.1, 
which gives a weight of 0.476 pound to the foot. 
Relation of wos Calculated 
Original or 
Gc Depih to} gasrock to =} 3 ressure 
Locations. gas. sea lawell Beatiobapi ed) 1 foot—0.476 
(below tide).| Pressure: pound. 
on. Feet. Feet. Pounds. Pounds. 
Tiffin, Loomis & Nyman well .....-...........-- 1, 500 747 650? 641 
Upper Sandusky, well No. 1.-..-...-...-...-.... 1, 280 478 515 5138 
Bloom Township, Wood County, Godsend well.. 1, 145 395 465 473.6 
Jabal hy, Les eay Gla Seo pessescer secsnnocessc=c 1, 120 336 450 445.7 
Sits Mibiay sy Beall Aanosacosondseasecs0cocusse 1, 159 238 390 398. 8 
St. Henry’s, Dwyer well, No.1.................- 1, 156 200 375 385 
INDIANA. 
TEGO yell Ws feos oascbeapassecdoucosaagasdes 936 98 320 332 
WeyeGye, Wel IMs Bo con dconcsanHsoossscoonsncoeeds 870 78 323 322. 7 
MRIMICIOS Sey. Saeed ceicinine eRe ecmie tase eciee Sees 900? (*) 300? 286. 6 
* At tide level. 
These figures seem to me to settle the question as to the origin of the 
rock pressure of the gas in this formation. I feel sure that nicer de- 
terminations of the facts involved as to altitude and depth would bring 
a still closer agreement between columns four and five. I will ask you 
to note in particular the facts as to the St. Mary’s and the St. Henry’s 
wells. They have practically the same depth, 1,159 and 1,156 feet; 
but there is a difference of 38 feet in the depth of the gas rock with 
reference to sea level. There is a corresponding difference in the rock 
pressure of 15 pounds, as recorded. The difference in rock pressure 
due to this 388 feet by calculation is 13.8 pounds, or, practically, 15 
pounds. I presume that column five is as near the truth in this par- 
ticular as column four. The gauge would quite certainly be reported 
385 pounds if it lacked but 1 or 2 pounds of that number. 
THE LAWS OF GAS PRODUCTION. 
The laws of gas and oil production and accumulation are coming to 
light more clearly in the flat country of Ohio and Indiana than they 
have ever done among the hills and valleys of the older Alleghany 
fields, As it seems to me, no more important deduction from the new 
