On the Measurement of a Base on Epping Plains. 61 
By the kindness of Prof. Fairman Rogers I have been enabled 
to collect approximately some of ew statistics of the measure- 
comparison with the other five Coast Stace bases which I have 
measured. 
EPPING BASE.—TABLE I, 
Whole length of base i in tubes, —- - 1453 
metres, - - - §8718m 
iaaees added at east Se making - - 8719™4245 
or 28,607 feet, or about 5-4 m 
Diff. of level between ene aa sia ees: - 104 ft. nearly. 
Mean level of Base above n tide, 257 ft. or 7843 
Approx. corr. - ite uction rs ah level of the sea, - 010714422 
or 4 inches 
No. of tubes inclined, - ae re 643 
“evel, - - §810 
Ratio of tubes juiclined to whole number, -  0°442 nearly. 
level - - 0°55 
Gieetion ra versed sine te hak base, - 28038437 
_ or 9-2 ft. to be subtracted, *j 
Maximum inclination, 8° 14’ Somber inclined. 
Number of tubes inclined, 8° andover 31 0-048 
305.4 * Bea 0°364 
“ «“ “ “ “ é“ "9 0123 
Pater @ ooo ¥. 3054 “5190 0°186 
“ “ PN Sats 1 & “« 110 O171 
bad & «& “ 0 30 * een 0-032 
“ “ « “ 48 s ON 
643 
me day’s work si, ao 1:05 mile in 11 10™ working time. 
‘Averaging 1 tube in 2 
Greatest number in one oo 37, or 1™ 378 for each tube. 
Tk TABLE II 
__ Comparative Table of the Measurements of sir U. S. Coast Rie Bases. 
os he treraeadicdaeral. ered 
Dauphine | Bodies ; Edisto | Key Epping 
Island. | Island. iat Biscay ne Selle, Plains. 
Whole No. of tubes measured,| 1777 | 1807 | 1787 | 965 | 1072 | 1458 
“days 10 B 
" holies seg ee 143) 17"1814.08"/97: 2866: 31”| 46% 26" [69° 43” 
a tubes level, 961 | 1496 | 862 | 473 | 994 | 810 
a inclined, gi6 | 811 | 925 | 492 ae | 648 
"AE oth of working dy. Sn 25m 7Ts| 8407") Th 80”| 7A 23715448" 18*|104 07” 
— of one sabe, bm 821 9m 542| Bm 29s| 4m 207} 2m Ble | 2m 588 
in of tubes per day, | 1045 | 1807 | 1875 | 1072 | 184 | 1816 
“ No.of tubes ped’ ay of 9 $i, 1080 | 197°9 | 1659] 1800|, 2000 | 1872 
hour. 1185 | 2198 1840) 1440) 2247 | 208 | 
Ps inna, 17°6 | 1671 | 24%5°] B1'0 | 12/0 {1° 58) 
2 
iia 
+ 
& 
16 
“ of greatest vile inclin, 40'8 geet | 65"4 | 5870. | 14’0 2° §2' 
“ 4 
