

IH 



. the edge of the 



these have ordinarily 

 flowing around 

 soU either 



caisson, until urugrssa can 

 ion of 

 .ison is so rapid that it can 



vud from six to tin 



apiece Is the record for Kinking each of 

 caissons, some of which were 10 fast 



Water to the amount of about 50,000 gallons 

 *wn from the mains and delivered 



rsure tramps, and a 



^jrk is allowed t tank. 



><l used over again. It ho* 



ticablc to use one of the cais- 



SDflA< a M-tllnu' lank afl.t it h.i> I-.,,, 



[he bottom sealed with 



w are placed by the engineer m 

 tinea where the tract ural load 

 RThen all t d has In- 



n Mi.- intrrior of the caiswm the 



ww * 



Uk 



:& 



at i 

 tjl 



tlllrd n|. with a concrete, formed 

 id. and broken r if pre- 



>! int. It up with 



rv thui provided, reaching: down 



U nrr.-H*ur\. r. . t.f. r. .-I \-\ !.'..- 

 , and growing hanl.r with pro- 

 iron or steel caisson may 

 ugh corrosion in th.- course of a 

 this is not of thr slightest conse- 

 stirroundiiiK earth must at once 

 it dmwr to the 



r..|ist ril- t |. .Ji ..f 



.nt tin- pr...|nn 

 >rOM it.s-lf II|M.II 

 I riiLMin -r. A 



lluild- 



*::! f 



Mtttd 

 mai th) 

 law* not 



h brought 



f facts and opinions drawn from thr 



MiU-r*. Miinr of wh"in 



distinguished. ,,,. ,-. 



uoh strnctares is that thr forces to be 



ire not as yet very well understood. 



: partitions 



wise, particularly at great 

 (HI-. n..t been : riuinfjd itfc BWl 

 >f resistance for 

 tir.-. liko bridges, trestles, and 

 tors, an- u-tt.-r umlcnitood. Tf. 



. Itvd Utlllljlirrd 



Mir oaloo- 

 engineers have not 



building. :..:- u i and small, an- 



we, win the large 



sbove surround ing Htrurturv*. mu-t ! 



uld MIMII to U> 



method of 



.irlv adapted to resist, or 

 has been largelv over- 



riea accord 

 yet wholly understood. For instance. 



10.1W4 



rrarbed a 

 ' 60 miles an I 

 time, but wa. far more de*t 

 rtorm of >Un h L IW, which regiatoml 75 

 mill-* an hour and averaged M mile* 

 period of nearly twelve hours. The first meo- 

 tioned storm wa* from the norths**, a< 

 accompanied by heavy rain; the other wa 

 the northwest, without rain. 



SZ 



point of observatioi; 

 196 feet higher than that for thr flrt. Allow, 

 ing for all these differences, the March storm 

 ought apparently to have bean far more destruc- 

 itan its prsdsMssnr. The iwoorda of tu 

 two storm* an Ukm at thr (Vntral Park and at 

 thr 1' mied States Signal-Service Mat 



!y in all drlaiU fieri* rainfall. 



tods, Mr. Just very properly urges Ihe 

 ration of more ex* I data of thr total rr 



f wind rather than the maximum pras- 



ppsmrs to be that a wind accompanied by 

 dampness or by rain has far more rtsstnsrtJTSj 



than one that i rotn|*r' 

 The best modern practice in the c 

 fty building* appear* to be to 

 outer walls and thr 

 together, utili/ing floors am 

 mom u.i. IM betvn < . .- 

 will IH- ,l,.tni.ut.-.l from one wall to 

 and the whole structure be united in 



method should form a far 

 ring structure than was 



a stoat interior 



framework proix-rlv put together, the strength 

 of the wall* and their power of reaistam 

 forces from without is enormously incrcosfd. 



One of the chief dangers in steel construction 

 is corrosion. An instance is given in the ca*e 

 of a I w York, less than a gesjsjsj 



way for a modern structure, where the ends of 

 the beams had so rusted awav that i 

 could be broken off with the nWrs, Of 

 >ve process M this must 

 r a building less capable of resist- 

 ance to wind pressure in the course of a frw 

 years than it wa when first completed. Tbe< 

 of adequately protecting steel be* 

 . an* propefrj imbedded and 

 in masonry, wan intan< d in uoe of the great 

 ml. hue- in ' where an CXOSl- 



lai.l bn.k wall nearly 4 feet thi< k mm 

 M n-odih (rmrablr by water under 

 violent wind pressure from nod heart storms that 

 a considerable flow of moiMurr trickled down on 

 *idc. This was corrected by painting the 

 outside ..f thr wall. An. 4 her danger is that 

 when the parts of a steel stmctnre do not join 

 accurately, as, for instance, whoa a column b 

 not ventral .-n being set in position.it is too 

 a pract: workmen to correct 



t fault by .inritik' few nails undrr 

 the e<lg of the column until it is perpendicular. 

 or. whi. h i* a htllr U v. r. but Mill not com- 

 mendable. by Ming thin mo. called 



shims'* or M l>utrhmen." instead of nai 

 course, such makeshift devices sat at naught all 

 calculations for the permanent distribution of 



