393 
he noticed the rude adaptation of the quern stones to the 
purposes of a water-mill. 
From a curious book, entitled “the Montgomery Manu- 
scripts,” written about 1648, Mr. Smith quoted a description 
of a similar attempt in the Barony of Ardes, County of Down, 
in Ireland, to convert a hand-mill into one driven by water, 
in which “ the axle stood upright, and the small stones, or 
querns, such as are turned with hands, on the top thereof. 
The water-wheel was fixed at the lower end of the axletree, 
and did run horizontally among the water, a small force 
driving it.” 
In conclusion, Mr. Smith pointed out the progressive im- 
provement in the form of the quern,—from the pair of rude 
oblong stones, which ground the corn by simple tritura- 
tion, to the rotatory mortar-shaped quern; thence to the 
rounded or rather hemispherical form; and concluding with 
the two flattened stones, similar to those used in the water- 
mills of the present day. 
The Rey. Mr. Todd exhibited to the Meeting a fac si- 
mile of a remarkable papyrus roll preserved in the British 
Museum. 
The Secretary read the following communication, entitled 
« Justification of Mrs. Somerville’s Experiments upon the 
magnetizing Power of the more refrangible solar Rays.”* By 
George James Knox, Esq. and the Rev. Thomas Knox. 
Professor Morichini of-Rome was the first to observe 
that steel, when exposed to the violet rays of the solar spec- 
trum, becomes magnetic. Similar experiments were tried by 
Mr. Christie, in 1824; but the most accurate experiments 
upon this subject have been performed by Mrs. Somerville, 
in 1825, who determined that not only violet, but indigo, 
blue and green, develop magnetism in the exposed end of 
* Phil. Trans. vol. cxvi. 1826. 
