This chart is drvdded vertically into thirteen months in order to include the first month of the following year. Each month is further divided, 

 by the lignter lines^.into periods of six days each, except in the case of those months having fewer or more days than 30, when the last division 

 of the month'may equal four, fi.ve, or seven days. The ist, 6th, 12th, i8th, 24th and last days of the month fall on, the vertical lines. The 

 transverse, lines ^represent the, stations, from, which they: extend. A complete break in the isothermalline opposite any station generally indicates 

 chat the temperature did notxeach the isotherm at that station during the year. A line consisting of dashes denotes a lack ot observations fot 

 the corresponding station. 



