10 -W. W. Mather on the Meteorology 
23, 24. pe weather; wind not noted. | 
25. Ple t weather, very fine day; but in the afternoona + 
me ee from me mar: ke, it benaiejeidcleny socold 
; Pleasant ; * wcinds not sféted:: Getierally. at this season 
oft pric’ year calm, or with moderate winds during the warmer 
part of the day, and : a — + get in the =) tas irom S.8.E.at || 
Pi ing. a 
29. Clear but very sy sity a yi wind ah the south. ~ 
bore aqui of water on the. 
30. ore a. on as Hom very cold, not noted. 
“noted. soon a ra as I wed thie arti- 
—= apy viding. iu -aniddlo‘of iow hays wind: nét 
ite Me oy without maid with sextant. . 
2108. 27 eonagint ater (rom revatio, t not lary. 
at Copper Harbor, on Porter’s Island. .- 
» On the 7th of July, Dr. C. T. Jackson kindly inejlis me with 
ig by means of which a register has been kept: mite 
6 the barometric pressure, with the ee 
beth os sone force of winds, variations in the lake level, & 
thermometer detached from the barometer, corresponded writh be! 
attached thermometer within less than half a degree, and only 
on secietered except where a fire was made in the room, and 
tl e detached thermometer »was removed to the outside of 
the buil dig with a proper exposures, © ¢ © 
‘During this calm season of the Year the surface of the lke 
water becomes warm, while alittle below the surface it is quite 
cold. He northerly winds, which: make the air “cold, drive 
ture of the water of th notth side of P nas 
calmer petodnes the’simmer. “ a a 
RR ek ee foam age A 
ait Bw Ay # age he 
