256 Mr Cruickshank mi Atmospheric Refraction. 



ject was from twenty to twenty-one miles. The straight line join-, 

 ing it and Aberdeen, passes above the land for about a mile and 

 a half, reckoning from Aberdeen, and about half a mile on the 

 Buchan coast. The remainder of the line passes over the sea ; 

 and its greatest distance from the shore is about a mile and a 

 quarter. The sands of Belhelvie occupy the greater part of the 

 intervening coast. The observations were continued for half an 

 hour, by the end of which those extraordinary phenomena had 

 become less striking, and could not so easily be observed, owing 

 to increased tremor in the atmosphere. There was no fog in 

 the direction of the object during the observations. The at- 

 mosphere was rather warm ; but I regret that I have no record 

 of the stale of the barometer or thermometer at the time. At 

 eight in the morning and nine in the evening of the same day 

 the thermometer was at 5G° of Fahrenheit. 



Analysis of Galena, J'ron Castleland Hill, near Inverkcithing. 

 By Mr A. Robertsom junior, Inverkeithing. Communi- 

 cated by the Author. 



This ore is partly massive, and partly in very regular octa- 

 hedral crystals, some of them almost as large as a pullet's egg. 

 It is found very near the surface, at the foot of a small hill, in 

 a piece of ground, which, till the drain was cut, which at pre- 

 sent carries off the water, must apparently have been a marsh, or 

 perhaps the bed of a small lake. It is contained partly in green- 

 stone, partly in a quartzy sandstone, both belonging to the coal 

 formation. It appears to have been disposed in a vein, not in 

 a bed, or irregularly intermingled with the neighbouring rocks. 



This vein was first discovered, about seventy years ago, in 

 cutting a road, and was wrought at that time, but without ad- 

 vantage. The working of it was resumed about thirty years 

 since, when nearly fifty tons of ore were raised, which, however, 

 did not pay the expense. It was abandoned shortly afterwards, 

 in consequence of a pretty extensive sliding in the greenstone 

 and sandstone of the strata, at a fissure between, which closed 

 up the greater part of the mine. 



Some of the crystals were carefully cleaned, and reduced to a 



