The letter L. sometimes inserted in the column of remarks on the state of the weather, indicates _lightning_; T. _thunder_, and R. _rain_. Observations, by means of the Cyanometer, on the colour of the atmosphere, were also made, three times each day, by Mr. Graham; but as the instrument became imperfect in consequence of the fading of its colours, from the necessary exposure to the action of light, they have been rejected. No record was made of the humidity of the atmosphere, as the Hygrometer provided for the use of the Expedition, proved entirely useless. Simultaneous meteorological observations were made at Germantown, near Philadelphia, by Mr. Reuben Haines; from which the average temperature of that place during several months has been deduced and inserted for the sake of comparison, in the following tables. Observations on the state of the weather were regularly made during the whole term of the expedition, but being too voluminous to be inserted in the work, it was thought best to select those of an entire year and reject the remainder. {xliv} _Meteorological Register_ {xlv} _for the Month of_ JUNE, 1819 =====+=================+=================+=================+=====+ | | | | | | | | | | Day | MORNING | MID-DAY | EVENING | | of +-----+-----------+-----+-----------+-----+-----------+Mean | Month|Temp.| Wind |Temp.| Wind |Temp.| Wind |Temp.| -----+-----+-----------+-----+-----------+-----+-----------+-----+ 1 | 68 | N.W. | 76 | N.N.W. | 77 | W. | 73 | 2 | 65 | Calm | 77 | W.N.W. | 75 | N.W. | 72 | 3 | 65 | Calm | 82 | S.E. | 80 | S.S.E. | 75 | 4 | 72 | Calm | 83 | Sy. | 81 | S. | 78 | 5 | 73 | S. | 85 | S.E. | 83 | Sy. | 80 | 6 | 73 | Calm | 85 | S.E. | 84 | E.S.E. | 80 | 7 | 79 | S.W. | 85 | S.W. | 84 | Sy. | 82 | 8 | 78 | S.S.W. | 83 | S.S.W. | 83 | S. | 81 | 9 | 75 | S.W. | 85 | S.W. | 80 | W.S.W. | 80 | 10 | 68 | S.E. | 83 | E.S.E. | 75 | S.E. | 75 | 11 | 64 | S.S.E. | 76 | W.N.W. | 72 | N.W. | 70 | | | | | | | | | 12 | 66 | N.N.E. | 73 | N.N.W. | 73 | N.N.W. | 70 | 13 | 68 | Calm | 78 | S.S.E. | 72 | S.S.W. | 72 | 14 | 72 |S.E. by E. | 81 | S. by E. | 80 | S. | 77 | 15 | 77 | S. by E. | 84 | E. | 75 | S. | 80 | | | | | | | | | 16 | 72 | S.E. | 84 | Calm | 86 | Calm | 77 | 17 | 80 | Calm | 87 | Calm | 86 | Calm | 84 | 18 | 80 | Calm | 86 |N.W. by N. | 81 | N.W.