720 
Proceedings of the Royal Society 
Rocks of North Rona collected in August 1880 on the North-east 
Spur of the Island. By Prof. A. Renard and John Murray. 
1. Amphibolic rock with a more or less schistose structure, fine 
grained, breaking in elongated fragments following the plane in 
which the crystals of hornblende are arranged. It contains espe- 
cially black brilliant hornblende with the cleavages of 124° 30'. 
Also quartz and some grains of feldspar. 
2. A rolled fragment of sandstone (Cambrian ?), red, fine grained, 
passing to arkose. This rock is essentially composed of fragments 
of quartz more or less rounded, of particles of hornblende, of epidote, 
of mica, and of more or less altered feldspar. 
3. Gneiss composed of lamellae of muscovite, plagioclase, ortho- 
clase, and quartz. 
4. Granitite containing plagioclase, orthoclase, quartz, and biotite. 
5. Amphibolic rock, almost entirely formed of an aggregation of 
crystals of black hornblende, whose dimensions are from 05 to 1 centi- 
metre, and show prismatic cleavage. Associated with the hornblende 
are granular quartz, lamellae of biotite, and orthoclase. 
7. Rolled pebbles of a clastic rock (Cambrian T) composed of 
fragments of quartz, more or less rounded, and red orthoclase. 
8. Gneissic rock formed of quartz, orthoclase, lamellae of biotite, 
and rather large crystals of hornblende. 
2. Notice of the Solar Eclipse of the 17th May, with Remarks 
on the Calculation. By Mr. Edward Sang. 
The eclipse of the 31st December 1880 was not seen here, and 
thus we lost the opportunity of comparing the computed with the 
observed times. 
In the daily papers at that time expression was given to a feeling 
of dissatisfaction that any computation should have been added to 
that recorded in the Nautical Almanac. And therefore, while 
laying before the Society the results at which I have arrived in 
regard to the coming eclipse, it may be proper for me to explain 
how such an investigation comes to be needed. 
