C | 200 | 175 | 280 | 455 || 450 | 270 | 380 | 650 __________|_______|_______|_______|_______||_______|_______|
_______|_______ ____________________________________________________________
_______ | | | | || | | | Pressure |IV_{1}|IV_{3}|IV_{3}|IV_{3}||IV_{2}|IV_{4}|IV_{4}|IV_{4} per square|Earth.|Earth.|Water.|Total ||Earth.|Earth.|Water.|Total foot at | | | |earth || | | |earth | | | | and || | | | and | | | |water.|| | | |water. __________|______|______|______|______||______|______|______
|______ | | | | || | | | A | 1,370| 1,210| 100 | 1,310|| 3,175| 1,910| 150| 2,060 B | 1,170| 1,030| 200 | 1,230|| 2,700| 1,610| 290| 1,900 C | 970| 855| 290 | 1,145|| 2,250| 1,355| 430| 1,785 D | 775| 680| 370 | 1,050|| 1,800| 1,100| 570| 1,670 E | 590| 515| 460 | 975|| 1,350| 820| 710| 1,530 F | 400| 350| 560 | 910|| 900| 540| 860| 1,400 G | 190| 170| 650 | 820|| 450| 275| 1,000| 1,275 __________|______|______|______|______||______|______|______
|______

FOOTNOTES: 

[Footnote A:  Presented at the meeting of May 18th, 1910.]

[Footnote B:  Transactions, Am.  Soc.  C. E., Vol.  LX, p. 1.]

[Footnote C:  Engineering News, July 1st, 1909.]

[Footnote D:  From “Gravel for Good Roads.”]

[Footnote E:  Transactions, Am.  Soc.  C. E., Vol.  LXVIII, pp. 58-60.]

[Footnote F:  “Discoveries and Inventions of the Nineteenth Century,” by Robert Routledge, Assistant Examiner in Chemistry and in Natural Philosophy to the University of London.]

[Footnote G:  Engineering News, January 15th, 1909.]

DISCUSSION

T. KENNARD THOMSON, M. AM.  SOC.  C. E.—­Although the author deserves great credit for the careful and thorough manner in which he has handled this subject, his paper should be labeled “Dangerous for Beginners,” especially as he is an engineer of great practical experience; if he were not, comparatively little attention would be paid to his statements.  The paper is dangerous because many will read only portions of it, or will not read it thoroughly.  For instance, at the beginning, the author cites several experiments in which considerable force is required to start the lifting of a weight or plunger in sand and water and much less after the start.  This reminds the speaker of the time when, as a schoolboy, he tried to pick up stones from the bottom of the river and was told that the “suction” was caused by atmospheric pressure.