261 
ON INSTRUMENTS FOR MEASURING THE SPEED OF SHIPS. 
Table of Results of Mr. Frovpn’s Experiments with the Apparatus described in his Memorandum. 
Distance | Depth of “ 
zal Diameter |of pressurelimmersion F aan pontine” Pressures recorded for various “angles of position” (that is, angular distances of hole from front side of tube) 
of pressure pt sure) hole from |, of lower | ¢ yressurelof “netitral at a speed of 6 feet per second. 
tube; ole. ee = iy en - eine | point.” The several “angles of position” head the several columns. 
in. in. in. in. in, ic 0° 10° 20° 30° 50° 55° 70° 90m |e Leap? 180° 
(1-42 0:05 4 16 12 374 549 506 a0 bn nie es — 496+, —345F)  ... — 368 
| 1-42 0:05 4 13 9 374 048 = oes = soe aes — 502 | —-368 < — 379 
ie yl be 0-15 4 16 12 39°3 556 +528 eee wie sts ie —'552 | —'379 oe -—'379 
La tae ne ae re ty ae es i nis 5 ns —770 | (t) — 787 | —-528 
“ae "Ud . ‘0 ¢ E eee eee eco eee wen ade eae eee oes 
1-42 0-05 12 15 3 38:0 B49 eo san oe me sos — 476 | —-368 oes —°370 
1-42 0-05 12 21 9 36:4 546 ais Bt 70 ee oe —'632 | —404 Tee —620 
142 | 005 | 12 15) |= 2B | o88d “Saab le a, am ih “i ieee er ey a is 
142 | 005 | 12 18 6 373 | +549 + +: ai uf - =5a0e “ys =i ‘s 
1-42 0:05 4 13 9 376 545 ae Str aes me we — 505 | —'345 eee —368 
1-42 0:05 4 19 15 36'9 552 R.. wer oes “39 eae — 511 | —:379 wa — 414 
1-42 0:05 1 16 15 35:2 538 ase << oe S5¢ ors — 804 | —-747 26 — 575 
1-08 0:05 12 15 3 373 047 Ree nee ae oor “ine —‘dd1 | —-414 Rie —402 
1-08 0:05 12 21 9 36:1 542 a oe Sa = ave — 666 | —-534 wee —'O75§ 
1-08 0:05 4 13 9 38:2 651 Rs wee ane — 269 fs —'494 | —-356 eels — 379 
1-08 0:15 4 13 9 40°6 D47 Sas oe Sed —'225 a —d17 | —391 Sc —'373 
108 0:05 i 7 6 37:3 545 pi awe Suc — ‘292 om —'572 | —414 oar —402 
1:08 | 0-05 0-5 7 65 37°3 “531 tee it oe —296 |... —609 | —425]  ... — 437 
108 0-15 0:5 7 65 39°5 DSL 1% 2 =f — 255 Es a am pF — 
108 | 0-15 4 7 3 429 | -550 | (535 | -484 | 271 ae — 930 | =-368 | —-218 | —-241 | =-218 
1:08 | 0-05 4 7 3 405. =)" 549 5 |e “2. 402 ts ms —-264 | —333 | —-218 | —-224 | —-207 
05 0:15 4 7 3 45°5 549 “a pe 326 sire —:225 | —460 | —333 | —-333 | —322 | 
N.B.—The pressures are throughout given in decimals of a foot, and give the true pressure, not that actually read off the instrument. The theoretical head or 
pressure due to 6 feet per second is ‘536 feet. 
* These results were obtained before the ‘“ water-deck ” was fitted. + Really taken at 674° and 874° respectively. 
+ Less than —-800, but could not be read off, being below the index-tube. § Really taken at 1774°. 
