Two rain gauge measuring cylinders.

"Mr. Tornaghi for the Sydney Observatory has also constructed numbers of tide-gauges, standard barometers, self-registering barometers, micrometer eye-pieces, and numberless other instruments of importance."

Tornaghi was born Milan in 1831 and arrived in Sydney in 1858 to supervise the adjustment of the Negretti & Zambra instruments ordered by Sydney Observatory.

By 1861 he had set up his own business at 28 Bridge Street Sydney and was acting as a local agent for the London based Negretti & Zambra. It was during this period that Tornaghi also started making instruments himself and by 1864 he had moved to larger premises at 312 George St Sydney.

Rain gauges were an important feature of the observatory's work and they not only brought their own gauges but provided instruments to other meteorological stations around New South Wales. It then collated data from their own gauges and those located at other stations around New South Wales. By 1860 meteorological observations, including rainfall, were being systematically collected every month and sent to the Observatory.

This instrument remains of national significance due to its pioneering role in Australian science and its association with Australia's earliest astronomers. It is also significant for its association with nineteenth century meteorological instruments and local instrument makers.