. Water & sewage works . ally during crowdedhours or in such emergencies as enough height Is available, acurved form generally looks better thana straight one, tho the latter leaves morespace for the passage of boats and rivercraft. The design of bridges Is also greatly in-fluenced by the angle of the crossing,whether square or skewed, and by the ap-proach grades. Double leaf bascules arethe best form for decorative treatment,for the outline of the two leaves can bemade symmetrical, and if the movingspan forms a part of a long viaduct, suchas those at First and Sixteenth streets,the
. Water & sewage works . ally during crowdedhours or in such emergencies as enough height Is available, acurved form generally looks better thana straight one, tho the latter leaves morespace for the passage of boats and rivercraft. The design of bridges Is also greatly in-fluenced by the angle of the crossing,whether square or skewed, and by the ap-proach grades. Double leaf bascules arethe best form for decorative treatment,for the outline of the two leaves can bemade symmetrical, and if the movingspan forms a part of a long viaduct, suchas those at First and Sixteenth streets,the bascule curves might be made to cor-respond with others in the adjoiningspans. Single leaves are not artistic, forthey lack sjTumetry. A combined bas-cule and cantilever, such as that patentedby Mr. Newton, of Milwaukee, has a great-er clear width between the piers, but theleaves, when raised, are unprotected, andnone of this kind have yet been built. A curved outline for the bottom chord. July IJli MUNICIPAL ENGINEERING. HOLTOX STREET LIFT BRIDGE, Milwaukee, Wis. as on the Broadway bascule, usually lookswell, and is suitable when the necessaryheight is obtainable, the form being usedin 1S39 for the Ouse river bridge atSelby, England, which has for half a cen-tury been the prototype for later is rather unfortunate that such de-signs as those at Stettin over the Oder,and at St. Petersburg over the Neva, havenot been introduced in American cities,for they are not only commodious but arequite as attractive as any other beautifulcity feature could be. Indeed they aremuch more prominent than beautifulpark bridges, because of their location inthe center of the city, where they can beseen by great multitudes daily. Double leaf bascules are quite unsuitefifor railway service, as was proven priorto 1S71, at Rhyl, where such a one wasfound to be a failure, because the centerlock was insufficient to insure safe pas-sage of locomotives from one leaf to theother. Notwithstanding thi
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectsewerage, bookyear191
