-1822.] - Rev. W. Ritchie on impelling Steam Vessels. 361 
shades of colour were employed at once. These circumstances 
may open up an extensive field for investigation to those philo- 
sophers who delight in speculations regarding the ultimate atoms 
of bodies, and their peculiar shape. In the whole of these 
examples of ductility we find that the atoms of the glass have a 
tendency to retain their original form although its magnitude be 
diminished ; the square, the oblong, the circular, the fluted and 
hollow rods, were still in the soft and silky threads to which they 
‘were spun, of the same shape as at first. Can the shape of the 
atoms, or any modification of the power of attraction, give rise 
to this? It is evident that the same portion which occupies the 
-angles of the large piece of window glass will be extended over 
‘the angles of the spun threads ; and the same is illustrated in 
another point of view by the many coloured glass rod, the 
shades of which retained their order and distinctive character. 
The last experiments were with glass rods of different colours; 
the most of the colours appeared to have faded by the operation, 
particularly the yellow, which in some trials was nearly gone; 
the black became brown, and the purple and green were some- 
what altered ; the blue seemed to suffer no change. The white 
glass, coloured with arsenic, was very brittle. 
The most of these specimens of spun glass are remarkably 
‘soft, like silk, and can be easily rolled up in the manner of com- 
mon thread, and platted into ornaments. To the feel they 
resemble the hair of the head; that spun from black glass has 
often been mistaken for. brown hair; it resembles the hair in 
another respect, for it retains the curls communicated to it by 
rolling it round a hot iron, 
Note.—The letters A, B, C, D, in this paper, refer to the spe- 
cimens which were handed round the Society, for the inspection 
of the members. 
ARTICLE IX. 
A Proposal for impelling Steam Vessels by horizontal Motion 
instead of Circular. By W. Ritchie, AM. Rector of the Royal 
Academy at Tain. 
(To the Editor of the Annals of Philosophy.) 
SIR, 
Ir you consider the following speculations worthy of a place 
in the Annals of Philosophy, by inserting them you will very 
much oblige, Sir, your obedient servant, 
WitiiaM Ritcuie. 
