AN IMPROVEMENT IN THE SCALES OF. ANEROID; BAROMETERS AND OF MERCURIAL BAROMETERS
Year: 1864

page_text: (This Invention received Provisional Protection only.)
"
PROVISIONAL SPECIFICATON left by John Barker Huntington at the
Office of the Commissioners of Patents, with his Petition, on the
16th September 1864.
I, JOHN BARKER HUNTINGTON, of No. 3, Furnival's Inn, in the City of
London, Engineer, do hereby declare the nature, of the said Invention for
"AN IMPROVEMENT IN THE SCALES OF. ANEROID; BAROMETERS AND OF MERCURIAL
BAROMETERS," to be as follows:
The dials of circular and of aneroid barometers (as heretofore and at present
in use) have usually engraved or printed thereon certain circles, which are
divided on their circumferences into five or more equal divisions, each repre
senting one inch of column of the ordinary mercurial barometer, and the said
divisions are also subdivided into tenths and hundredths, representing corre-
spondingly tenths and hundredths of inches of the mercurial column. The
aneroid barometer has been found to be a convenient instrument, available
for the purpose of taking the heights of hills or mountains, or the difference
of levels between one situation and another. But to effect this for the require-
ments of engineers, travellers, or philosophers, because the heights observed in
inches, tenths, and hundredths of the barometer do not uniformly progress with
the heights in yards, feet, (or other units of measure,) of the objects above
a given level (such as the sea level, for instance,) it is necessary to have recourse
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page_text: to a series of complicated calculations according to rules already laid down by
eminent philosophers, and contained in their works and in many well-known
scientific publications, and by such means the heights in yards, feet, (or other
units,) as required are ascertained.
The improvement in the scales of aneroid barometers which forms the
subject of this Invention consists in thé substitution or addition of certain circles
divided on their circumferences into divisions, each representing one thousand
or one hundred feet or yards (or whatever units of measure may be best
adapted for practical purposes), the said divisions being again subdivided into
tenths or hundredths. I propose to make the zero of the scale commence
with that division of the common aneroid barometer corresponding to thirty-
one inches of mercurial column, because that is practically the highest point
to which the mercury is likely to rise at the level of the sea, but I do not
bind myself to this zero only, which may be made to commence at thirty or
any other number of inches of the mercurial scale. The divisions of the
improved scale are to be engraved or printed on the dial (having been pre-
viously calculated accurately according to the scientific rules already
referred to bearing on this subject,) in such manner that as many yards
or feet or other units as are read off the scale of the dial, at where the
hand points to, sball truly represent the height above the sea level, the
same as though the barometric height were read, and the corresponding
height in yards or feet (or other units) were afterwards computed according
to the said rules.
The advantages to the observer will be a great saving of time, and the
elimination of chances of error in calculation, because, immediately on inspec-
tion of the dial, he will ascertain the height of any place where he then is, so
that by taking observations at any two places in succession he will know at
once the difference of levels between the two places by the simple operation
of deducting the one observed height from the other.
: I propose to call this improved instrument or scale the "hypsómeter," that
is measure of altitude," to distinguish it from the ordinary barometer. There
is nothing in this improvement in the scale to prevent the mercurial
scale from being engraved either within or without the circumference of the
hypsometer, so that the observer may register from one or the other at his
pleasure.
A variety of the said improvement consists in engraving or printing on
the dial a curved line of the spiral order so contrived that 'all the
divisions thereof will be equi-distant, as in the ordinary barometer, instead
of containing spaces increasing or diminishing progressively, as must be the

page_text: case if the graduations be applied to the circumference of a circle. The
improvement before described is also applicable to the scales of mercurial
barometers.