IN THE HALL OF THE ROYAL SOCIETY. 
541 
The curve of the hot glass was so great that the workmen could scarcely pre- 
vent it from touching the pavement, (which of course would have caused its 
instant destruction,) by holding its extremities above their heads. While it was 
still red-hot and pliant, it was carefully laid upon the transverse pieces in the 
box, and rolled backwards and forwards till cool ; by which a perfectly cylin- 
drical form was secured. While the drawing process was going on, others of 
the workmen fanned with their hats, for the purpose of cooling, the parts which 
appeared to be extending too fast ; and by such simple means a tube was 
perfected without a flaw, and of the greatest regularity ; varying only from 
one inch diameter at its lower extremity to 08 inch at its upper. 
The facility with which this process was conducted was so much greater 
than had been anticipated, that I immediately determined to have another tube 
made ; that in case of any accident happening to the first, during the after 
operations, all the preliminary labour might not be thrown away. This 
was accordingly effected by rolling it upon the steps of a ladder placed hori- 
zontally upon the ground for that purpose. After it was cool it was lifted into 
the box by six men standing at equal intervals apart, and carefully placed by 
the side of the first. The box was then packed with hay, the cover screwed 
down, and carried upon men’s shoulders to a convenient place for the further 
operations. 
As it was not intended that the tubes should ever be removed from the case 
in which they had been originally deposited, the first step was to prepare the 
means of fixing them in their proper places when raised to the perpendicular 
position. For this purpose pieces of wood were provided of half the depth of 
the box, upon the upper edge of each of which a semicircle was hollowed out 
of the exact dimensions of half the cylinder of the tube. These were placed 
under the tube at equal intervals ; and other similar pieces prepared for screw- 
ing down upon the upper side of the tube ; in such a way that the two semi- 
circles meeting, formed collars, which tightly embraced it, and fixed it in the 
centre of the box. The corners of the lower pieces were also cut away so as to 
inclose the spare tube (e,/‘), Plate XIX. which was placed in one of the angles 
of the case, and thus tightly fixed. The next object was to prepare the tube 
(a, b) itself for its final fixture ; and for this purpose, as it was longer than was 
necessary, three feet were cut off from its upper extremity with a file ; a small 
4 A 
MDCCCXXXIJ. 
