272
would ring bells (like those already in use on railways to communicate among the
carriages of a train) to warn if the temperature of a given area ranged beyond certain
limits, and in this way detect the early phase of a fire (Telegrafi 1866). The thermoelectric fire alarm device consisted of twenty-one safety thermometers, two
Leclanché electric batteries, and the telegraph. This was integrated with a complete
Fig. 16.4 Autograph sketch by Father Angelo Secchi depicting the arrangement of water tanks
and the pipeline system in the Basilica of St. Paul Outside the Walls [1870] (APUG, Carte
A. Secchi, cart. 2, fasc. XI)
M. Calzolari and S. Marsella
would ring bells (like those already in use on railways to communicate among the
carriages of a train) to warn if the temperature of a given area ranged beyond certain
limits, and in this way detect the early phase of a fire (Telegrafi 1866). The thermoelectric fire alarm device consisted of twenty-one safety thermometers, two
Leclanché electric batteries, and the telegraph. This was integrated with a complete
Fig. 16.4 Autograph sketch by Father Angelo Secchi depicting the arrangement of water tanks
and the pipeline system in the Basilica of St. Paul Outside the Walls [1870] (APUG, Carte
A. Secchi, cart. 2, fasc. XI)
M. Calzolari and S. Marsella