Today I added a meteorological instrument catalog from J H Steward of the UK, undated but probably from the 1930s.  I also added my two mercury barometers to the instrument collection section.  One is a Henry J Green Observatory Barometer in working condition.  The other is a Henry J Green Mountain Barometer from 1885 - 1890 which does not have mercury in it.  I included for download a Microsoft Excel spreadsheet to calculate the local pressure and sea level pressure from mercury barometer data. Comparisons of the mercury barometer measurements with several common digital barometers are also provided.