This mercury marine barometer is labeled IMD, which stands for Indian Meteorological Department. It appears to be a Kew pattern fixed cistern barometer, except that the cistern is made of brass instead of the usual steel. It looks unused and like it has never had mercury in it. The seller shipped it in what appears to be the original wooden crate, it's in pristine condition. The scale is in millibars only and ranges from 870 to 1040 mb. It has a rack and pinion thumbwheel for taking the reading. It has a spirit thermometer ranging from -10 to 50 C.

On the lower half of the barometer is the later version of the Gold Slide, which is a brass slide rule device for shipboard use, used to calculate the total barometric correction directly on the barometer. The later version has the temperature scale in degrees Celsius, the earlier version in Kelvin. The user adjusts the sliding elements to the current latitude and the height of the barometer above the sea. The total barometric correction can then be read opposite the thermometer reading. Ernest Gold proposed the Gold slide in 1914. However, Gold slides were also retrofitted on earlier barometers. The Gold slide also has the initials IMD on it.

I have no idea of the date when this barometer was made. The IMD was founded in 1875. I suspect the barometer is post-Indian independence (1947) and made in India. I found it in Australia. If anyone has information, please contact me.