of Edinburgh , Session 1866 - 67 . 141 
found running north and south, sometimes nearly straight, but 
often curved, with its convex side towards the east. The minimum 
line of barometer was easily fixed by consulting the self-register- 
ing: barometers. The minimum line of barometer was shown to have 
been on the meridian of London at 8 a.m. of the 3d December, and 
apparently nearly straight from Algiers to the Orkney Islands. 
The barometer along the line of minimum barometer gradually 
descended from upwards of 30 inches in Algiers to 29 inches 
a little to the south of London. From London to the Shetland 
Islands the minimum barometer was isobarometric in its character 
— the pressure varying little over a distance of 600 miles. The 
isobarometric lines were shown to run parallel to each other over 
Spain, the Mediterranean, and south of France, and joined to 
the minimum line at an obtuse angle. Where the difference of 
pressure on the latitudes from the middle of France to the south 
of England was considerable, they were ribbed in from both sides 
at acute angles. Where the minimum line assumed the character 
of an isobarometric line, the isobarometric lines on the east were 
nearly straight and parallel to each other. On the west, they were 
much of the same character, especially about a hundred miles west 
of the minimum line. It was shown that curved lines could not be 
put in over France on the 3d December storm, according to the 
barometrical readings as given in the Paris Bulletins. 
The isobarometric lines were shown to have been similar in their 
character on the morning of the 2d ; that, however, they were flatly 
ribbed into the minimum line of barometer over France and 
England, and corresponded with the diagrams of the self-register- 
ing barometers at Oxford, Kew, and Greenwich. The effects of the 
storm of the 3d, then out into the Atlantic, were shown on the 
lines in contrast with those of the latter date. 
It was shown that the winds on the west side of the minimum 
barometer were from the west and north-west — the only exception 
to this being over the north of France and south of England, 
where south-west winds were observed at those stations where the 
isobarometric lines were kneed in towards the minimum line of baro- 
meter. At those places they mostly blew right across the isobaro- 
metric lines. At other places to the west the winds blew obliquely 
or directly across these lines towards the minimum barometer. 
