entury instrument-maker were unequal to
the task. It should also be noted that the photographic and
electromagnetic systems of the 19th century seem to have been something
of an interlude, for some of the latest and most durable (all of
Draper's and Richard's instruments and Marvin's barograph) were purely
mechanical instruments, as had been those of Hooke and Wren. If we
conclude that the 19th-century instruments were more accurate, we should
also recall Forbes' comments upon the question of instrumental accuracy.

What, then, was the essential difference between the 17th and 19th
centuries that made possible the development of the self-registering
observatory? It would appear to have been a difference of degree--the
maturation in the 19th century of certain features of the 17th. The
most important of these features were the spread throughout the western
world of the spirit that had animated the scientific societies of
Florence and London, the continued popularity of the astronomical
observatory as an object of the philanthropy of an affluent society, and
the continued existence of the nonspecialized scientist. Under these
circumstances such nonmeteorologists as Wheatstone, Henry, Hough, Wild,
and Secci had the temerity to range over the whole of the not yet
compartmented branches of science and technology, fully confident that
they were capable of finding thereby a solution to any problem important
enough to warrant their attention.

FOOTNOTES:

[1] On early meteorological instruments see A. Wolf, _A History of
Science, Technology and Philosophy in the Sixteenth and Seventeenth
Centuries_, New York, 1935, and E. Gerland and F. Traumueller,
_Geschichte der physikalischen Experimentierkunst_, Leipzig, 1899. On
the recognition of the meteorological significance of the barometer by
Torricelli and its meteorological use in 1649 see K. Schneider-Carius,
_Wetterkunde Wetterforschung_, Freiburg and Munich, 1955, pp. 62, 71.

[2] Bacon's book emphasizes "direct" and "indirect" experiments, and
calls for the systematization of observation, but it does not mention
instruments. It is reprinted in Basil Montagu's _The Works of Francis
Bacon, Lord Chancellor of England,_ London, 1825, vols. 10 and 14.

[3] Wolf, _op. cit._ (footnote 1), pp. 312, 316-320. The interest of the
Royal Society in the barometer seems to have been initiated by
Descartes' theory that the instrument's variation was caused by the
pressure of the