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POPULAR SCIENCE REVIEW. 
your left, you can raise or lower yourself at pleasure, and 
observe with the telescope in any position. The whole obser- 
vatory only requires moving about once in two hours, and can 
be moved with ease by one hand. 
Within a year of its being begun, the telescope was rapidly 
approaching its completion. The great speculum had been 
brought to the right shape, and was partially polished, and every 
day the announcement was expected that it was completed, or 
at least only required the final finishing touches. Suddenly a 
telegram arrived — an ominous thing. Was it to announce an 
imperfect figure ? This would be a most annoying thing, for 
it would require the whole to be reground and repolished. But 
no, it was very brief, but it announced a terrible misfortune. 
It was a pressing request to come down at once. The whole 
speculum had burst into a thousand pieces. 
It was a terrible blow, for it was the very misfortune which 
had been prognosticated by the English manufacturers and by 
the greater number of astronomers, including those who had had 
much experience in the construction and use of specula. The ex- 
plosion had been terrific. The whole workshop was covered with 
jagged, torn masses of glass, varying in weight from ten or twelve 
pounds to an impalpable dust. Mr. Calver had had a narrow 
escape, but he and his workmen escaped without serious injury. 
The monetary loss was great, and bid fair to be greater, for with 
the loss of the speculum the rest of the telescope became use- 
less. It might well seem that they were right who held the 
view that large silver-on-glass specula were impracticable, as 
from the difficulty in annealing large masses of glass they might 
be expected to break at any moment. 
Within an hour or two of receiving the telegram announcing 
this terrible mishap Mr. Common was in the library of the 
Royal Astronomical Society. While there he was met by a 
friend, a fellow astronomer, who, being aware that news was 
daily expected of the completion of the great speculum, asked 
him for the latest intelligence. Mr. Common calmly handed 
him the fateful telegram. He was thunderstruck, for it was so- 
unexpected, and he was one of those who had looked for much 
gain to astronomy to accrue from the construction and subse- 
quent employment of this grand new instrument. After 
expressing, no doubt imperfectly enough, his sorrow, sympathy, 
and disappointment, he naturally put the question--- 61 What 
can you do now?” The answer came gently enough. 66 Do ? 
Why, I have telegraphed over to Paris to see if I can’t get two- 
more discs of glass. It will be one to spare in case of another 
explosion.” 
Success must crown indomitable courage like this. The new 
discs arrived, and were duly transferred to Mr. Calver. One 
