7 8 
The contract for this bridge was made in November, 1863, 
and the bridge was erected during the past Summer. 
Mr. Worthington also exhibited a piece of cast iron lately 
taken out of the Sankey canal. Its exterior, from one-eighth 
to a quarter of an inch in depth, was so soft as to be easily 
cut with a dull knife From the form of the casting he 
thought it very probable that it had not been in the canal 
more than five or six years. He stated that the water of 
the canal was strongly impregnated with liquids discharged 
from the alkali works in the neighbourhood of St. Helens. 
Mr. Sidebotham read the following communication from 
Mr. James Nasmyth, C.E., Corresponding Member of the 
Society, and exhibited the large and beautiful drawing to 
which it refers — 
On the 5th of June, 1864, between the hours of 11 a.m. 
and 2 p.m., I had the good fortune to observe under unusually 
favourable circumstances, a large and remarkable group of 
solar spots. 
The willow-leaf shaped objects forming the structural 
element of the entire photosphere, as also forming the details 
of the penumbral portions and bright margins of the photo- 
sphere overhanging the spots, were occasionally revealed with 
perfect distinctness; but the favorable moments for pure 
definition had to be watched for, by keeping the eye steady 
at the eye piece and the hand on the focal adjustment, so as 
to be ready to make those minute focal adjustments that I 
find are requisite to meet the constantly varying condition of 
the atmosphere, which, especially during bright sunshine, is 
so fertile a source of defective definition, as is well known to 
practical observers. 
Some of the willow-leaf shaped objects were very favourably 
situated in an insulated position over the dark centres of the 
spots, and in that situation yielded me excellent opportunity 
for carefully noting their exact form and proportions. In 
