From office of Brigadier General W. H. 8IXBY. Chief of Engineers. Washington, D.C. D,NO sU Rf ACE LEVELS 0/r- 1&60 to I9JO. "C <% WWW tOA6 M* O . From office of Brigadier General W. H. BIXBY. Chief of Engineers. Washington. D C t ,.o SURFACE LEVELS OF T/ , F ^> i860 to_I9io. fy&i L C Control Number tmp96 026354 SURFACE LEVELS OF THE GREAT LAKES Curves of an nual means of each lake from I860 to 1910. LocAurr lerefs /h %1Z YEARS. af Jtor/Yar*. I860 1865 1870 1875 I8S0 1885 1890 1895 1900 1905 1910 1915 Igrefs in Hefaioye ffeonT/dc af A'crf }crk. LafreSaper/or of Mangi/efte G- 60229° />fean for i860 to fStO laAe Micfij^a aneffYaronaf flf/Avaahes -©- 68128* Mean for i860 to /9/0 lake Erie atCfereiana' -©- S72SS- Mean for I860 to /9/0 Lake Gnfar/o af faneao -©- 24629*. Afean for mo to f9/0 1303/ereb. /903 /ere/s. 603 €02 €0/ S83 S82 S8I S80 S73 S72 S7t 247 246 24S "T h s V? l:\ Vfj ' \ f ►. / - - - \ / $ s ■ S83 - "~- <' \ I Wp ,.'■ s .- M( jh' \ .. ' ■^ *■' l.ND * 'if ■ . ?&S Mil }.< ?!' %' ■■f i, J :■•,. ■ ■ 'l ■' -€ gf y $ E .; yk & 'A Ai( 1 / s / s ,j£ >0 V \ / \ V \ / ■s r .' -f ^ r *: ,( K' \l \ ■> / V ,' ^ \ Comparison of yearly means of lakes. M'chiga/t-hfcmn. fr/o & Ontario, separately and off together fcr 1360 to 19/9, each referred to its oxn mean. *■ 2 f / ± O - 1 - 2 . .. V /( I \ \ 1 lit N \ *, X ■/> .y. .--: 1 . ^ V / N - / \ " y i 1 > T •>\ > i 81 s, [ fc- * .^ \ 1 } \ 1 " -]-- h '4' 'r 1 7r - ¥' -,J «i/L -j ■*■ S/7 Under direction of Brigadier Bern Drawn in Office ot U.S. LoKe Survey, ral W. H. BIXBY, Chief of Engineers, Washington, D.C., November, 1911. Based upon Records of *>- s April May June July August September October November l£ve/s //j £ef ft/amadfyflfear T&teotf/m V&rh C'903 /eye/s.) 60S 604 603 602 60/ 600 - / - ^ A * r, ^3-' _/>-"" ^ a {$ * ° c-~ ' s, c — 2 _ Under directi Drawn In Off on of Brigadte ce of U.S. Lake r General W. H BIXBY, Chief of Engineers, Washington, V.C. November; 1911. Survey. Based upon Records of the Lake Survey ontt other U.S Enqineer Offices. SURFACE LEVELS OF LAKE MICHIGAN at Milwaukee, Wis. Lersfs m feef refenw/fe zera tysfar Afrfwavfcee Curve of Annual Means from i860 to 1910. Levefs /n feef refemdto Wear, TMte*f&*Mrk j (/303 foe/s) YEARS I860 1865 1870 1675 1880 1885 (890 1895 1900 1905 1910 91. +■ . *-* s / - - , \ i u . - \ ' 1 '-&— 7" \ * _ ' \ '■' ^ \ — 3 \ - - - s - s t / - 4 Zero of Af/fivaufee tf/ovge - S82.S3 afore Afear? fere/ Jbr /88S or /?/#/?est an/ruaf „ /896 ■■ /otyest - /lyemfes for Sf years or //ew y&rfrft/.S.LifAe Surrey /ere/ aa, us/went of /903.) ' mean = 58Z.96. rV/p/resf moatfi/y /wear? = S83.S7 Jc/ne, /886. - = 579.47 Lowest « - =578.98 Dec' / 8 95. £r /860 to f9fO /hc/= 58/28- foee -&-/'/? J/#e co/i//r?r?s.) Curves of Monthly Means between 1860-1910. j4= Corre of/886 or year ofA/ahest a/?s?c/a/ 'mean. 8=- - - arerapes tor S/ years, /860 fo /9/0. C - - - /896 or year of fewest annua f mean. S~ Represents the Average -for 5! years, i860 to 1910 inci = 581-28, lere/s />? /§*?/ referred 'A? zero ofgec-ge of BoeaAwafer Af//*v&vftee January February March April May June July August September October November December Ure/s if? £ef ra&rrea 'fo flfber/j T/cfeaf Marfok (/903 /enety 53* 583 582 58/ 580 579 * y " *■ 1 _ ■- ~ t -■■ 4 . - ^. -©— ? - B - " a ■ _ _, 1 - _- ' - t . Under direction of Brigadier General W. H. BIX6Y, Chief of Engineers, Washino+on, D.C., November; 1911. Drawn in Office of U.S. Lake Survey. Based upon Records of the U.S. Lake Survey and other U.'S. Engineer Offices. SURFACE LEVELS OF LAKE HURON at Harbor Beach, Mich. Levels in feet referred to zero of aauoe at tfarborBeach Curve of Annuo! Means from I87S to 1910. Ljeve/s in feet r&fsrnedto Mean Tide at New York (1903 Levels). YEARS I860 1865 1870 1875 1880 1885 1890 1895 1900 1905 1910 1915 ! ~~ s - , -Z =&=~ N ,. s \ \ > - " \ ^ N / \ ^ I — l - J - -stsi - / Zero of Harbor Beach qouoe =583.2 / above A/ew ybrk.tttS.Loke Survey /eref arfusfment of /303.) Mean level for 1886 or highest annual mear? = 583-08 Highest monthly mean = 583.€ 6. July 1876. 1896 or lowest » - = 579. S3 lowest - - -579, OZ. Dec. 1895. Averages for 36 years or tor 1875 to/3/0 incf. =581.13 (See -Q- in side columns.) Curves of Monthly Means between Jj£Z5^-I9IO. A = Curi/e of /8S6 or year of highest annuo/ mean. B= • .. Jvero tj es /or 36 years, 1875 to 19/0. C= - - IdSS or year of /owest annual mean. -©- Represents the average for 36 years, 1875 to 1910 incl. = 581.13. Levels in feet refarretfto zero of gouqe at Harbor Beach 4 iS £ ■» £ 4 -> ** -- B - - s / - - -. c Under direction of Brigadier General W. H.B1XBY, Chief of Enqineers»Washinqton,D.C. I Novernber ) 1911. Drown in Office of U.S. Lake Survey. Based upon Records of the U.S. Late Survey and o+her U. S. Enqineer Offices. SURFACE LEVELS OF LAKE ERIE at Cleveland, Ohio. levels in feet Curve of Annual Means from I860 to 1910. Levels in feet referred fo Mean Tide ai /Vetv)6r/c. (/SOS levels) referred to z.ero of oouqe at Cleveland , s6 o |ggr 1870 lf.75 1880 IS85 1890 1895 1900 1905 1910 1915 ■ + , ^ ±0 _,^. y£ V __ / \ *" - - _ - { 573 -'-&- H1LS/-1 r = ^ '\ ' \ J, / ~ ■• C\ 572 -2 \ > • -3 ' 4 Zero of Cleveland 6auge 57382 above Alew York (11. S. Lake Survey Levels of 1903. ) Mean Level for 1876 or Highest Annual Mean = 573-70. H/ahest Monthly Mean= 574-52.dune.l876. ■ 1895 ■ lowest • ~ = 571 ■ 17 . Lowest • - = 570-70. Mov.,1895. " Averages lor 51 Years or for I860 to 1310 the/. 57258 (se-e-Q-ln Side Columns) Curves of Monthly Means between 1860 — 1910. /?= Curve of 1876 or of highest annua/ mean . B* - - Averages for £1 years /S60- /Sto. C- ■■ ■ 1895 or of lowest annual mean. -^-Represents the Average for 51 years, I8€0 to 1910 incl. = 572-58. Levels in feet referred to t 1 ^ zero of gouge \*x £'1; >t ' ot Clevelond ->U-S- ^ ■ Lsve Is in -feet JO 01 \ p l-Q.q referred 'fo Mean %&%£ e ^ | « 7>We at /YewYorfc ^ « o O m