Royal Institution of Great Britain. 4Sft 



wind, and the like. The few inhabitants of the vicinity who were 

 awake, were alike sensible of the reports and noises ; but Sabaldy 

 the watchman, who was in the fields, besides the aforesaid noises, 

 heard the explosive sound of the fiilling of some heavy substance 

 on the ground, on that side where are situated the houses of the 

 sweepers, so that he went about on all sides in search ; but, in tha 

 night, nothing came to his sight. At length, in the morning, when 

 it was daylight, he was again moving about, in order to discover 

 what it was ; when on that side, at the distance of about three 

 fields from the cultivated land, he found that a stone, of the dimen- 

 sions of a span, had fallen down into the ground among the trees 

 of the common ; that a little smoke was rising from it, and that it 

 was somewhat warm : also, that the colour of it was just what it 

 now is. The light made it evident that this stone had the pre- 

 ceding night fallen from the atmosphere, and had occasioned the 

 sudden noise. It was also discovered that there had been a hole, 

 of the measure of one span, made in the ground, of which, in con 

 sequence of the violence of the rain, not a vestige remained when 

 the superintendent sent the stone to the Court-house. Its colour 

 appears of a red or rusty black, like that of iron. On one side a 

 little has been broken off, fi:om which the stone appears to be a 

 concrete mass. 



Mr. Ritchie produced one of his simple but delicate Balances. — ^ 

 See Quarterly Journal of Science, xxii. 181. 



Specimens of Pemmican, prepared by order of Government foi» 

 Capt. Parry's voyage, were laid upon the tables by Mr. Marshall. 



Experiment on the Reflection of Light. — ^The quantity of light re- 

 flected by bodies is known to increase as the angle which the incident 

 ray makes with the reflecting surface is diminished. This was 

 strikingly illustrated by a plane surface of plaster of Paris : used as 

 a mirror, no image of a luminous or strongly-illuminated body 

 oould be seen in it when the rays impinged directly upon the sur- 

 face, or at considerable angles ; but when the plaster was so held 

 that the rays made but a small angle with its surface, then a clear 

 and distinct reflected image of the object was immediately observed. 

 It was stated that even writing-paper, when well stretched and 

 brought into the proper position, could thus be made to act as a. 

 reflector. 



Several curious MSS. and antient books were placed upon the 

 table. 



2H2 



