Inside the Collection

Science Underground – … the most powerful and perfect spectroscope of its time

Spectroscope, made by Adam Hilger, 1876
Spectroscope, made by Adam Hilger, 1876, Powerhouse Museum, H9974

This spectroscope was made by the Adam Hilger of 192 Tottenham Court Road, London. It is also one of the earliest spectroscopes Hilger made as Henry Chamberlin Russell, Government Astronomer at the Sydney Observatory, ordered it in 1875; the same year Hilger opened his business.

After being tested it arrived in Sydney in 1876 and Russell appears to have been very happy with the workmanship. In his 1876 Government Report he described it as being the “most powerful and perfect one in the world at the time of its manufacture”. It was certainly well used as Russell connected it to the Observatory’s Merz 7.25-inch telescope to make spectral measurements. In 1878 it was also taken to the Blue Mountains to enable Russell to conduct tests to find out whether the performance of the observatory’s astronomical equipment was improved in the mountain air.

The spectroscope is an instrument which is attached to a telescope to spread light from the lens into lines of spectral wavelengths. This light is passed through a slit, and collimator, and then through a prism, or prisms, to disperse it into different wavelengths.

In 1859 Robert Bunsen and Gustav Kirchhoff worked out how to measure the spectrums cast by the spectroscope and began using it to identify the chemical constitution of substances in the atmosphere. Initially experiments focussed on the earth’s atmosphere but by 1860 a number of astronomers had begun to pioneer the use of spectroscopes for measuring the chemical composition of bodies in space.

One of the most significant events occurred in 1864 when William Huggins and W. A. Miller published their paper on stellar spectra. This identified elements from stars which were the same as those on earth and made it clear other planets, like the sun, had atmospheres as well.

References
Todd, David, P., Stars and Telescopes, Sampson Low, Marston, and Co., 1900
Chaldecott, J., ‘Printed Ephemera of Some Nineteenth Century Instrument Makers’, in Blondel, C., Parot, F., Turner, A., Williams, M., (eds), Studies in the History of Scientific Instruments, Rogers Turner Books, London, 1989
McConnell, A., Instrument Makers to the World; a History of Cooke, Troughton and Simms, William Sessions, York, England, 1992
Knight, E., H., (ed), ‘Knight’s American Mechanical Dictionary’, Vol III, J.B. Ford and Company, New York, 1874, p.2259
King, H., C., The History of the Telescope, Dover Publications, New York, 1955

One response to “Science Underground – … the most powerful and perfect spectroscope of its time

  • This post reminds me of a cautionary tale.

    In 1830 pilosopher Auguste Comte declared that the chemical composition of the stars is unknowable. Unfortunately for Comte’s later reputation, Joseph von Fraunhofer had already invented the spectroscope and used it to study the spectrum of sunlight, although it was left to Bunsen (the eponymous burner man) and Kirchhoff to explain the ‘Fraunhofer lines’ in the spectrum.

    Be careful when you state that something is impossible!

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