The loss of the quicksilver during the operation has been vary
variously estimated, some stating that it is 50 per cent. and more,
while others place it at 30 per cent. Escosura, in his work, gives the
details of an operation checked by a royal commission in 1872,
according to which the loss in working ore running 9.55 per cent. was
only 4.41 per cent.--a loss which he considered inevitable. In 1806,
two Idria furnaces were put up at Almaden, but the engineers are not
favorably impressed with them. The first cost is stated to be more
than ten times greater than that of an aludel furnace, while the
capacity is only 50 per cent. greater. One pair of Idria furnaces in
five years produced 120,000 kilogrammes of quicksilver, against
843,000 kilogrammes made by eight sets of the Bustamente furnaces, the
cost per kilogramme of quicksilver being respectively 0.121 and 0.056
peseta.
* * * * *
THE BALLOON IN AERONAUTICS.
While it is undoubtedly true that the discovery of the balloon has
very greatly retarded the science of aerostation, yet, in my opinion,
its field of usefulness as a vehicle for pleasure excursions, for
explorations, and for scientific investigations, has not been fully
developed for the want of certain improvements, the nature of which it
is the object of this paper to point out.
Pages:
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130