A NEW METHOD OF CONSTRUCTING THE HYDROMETER, AND ALSO A SLIDING RULE ADAPTED THERETO, WHEREBY THE REAL STRENGTH AND COMPARATIVE VALUE OF SPIRITUOUS LIQUORS, MALT WORTS, AND WASH FOR FERMENTATION MAY BE EXACTLY ASCINED
Year: 1780

page_text: DICAS SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, JOHN DICAS;
of Liverpool, in the County of Lancaster, Brandy Merchant, sendeth greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-seventh day of June, in the twentieth year of His
reign, give and grant unto the said John Dicas, His especial licence, full power,
and sole priviledge and authority, that he, the said John Dicas, during the term
of years therein expressed, might make, use, exercise, and vend, within that
part of Great Britain called England, the Dominion of Wales, and Town of
Berwick-upon-Tweed, his Invention of "A NEW METHOD OF CONSTRUCTING THE
HYDROMETER, AND ALSO A SLIDING RULE ADAPTED THERETO, WHEREBY THE REAL
STRENGTH AND COMPARATIVE VALUE OF SPIRITUOUS LIQUORS, MALT WORTS, AND
WASH FOR FERMENTATION MAY BE EXACTLY ASCERTAINED;" in which said Letters
Patent there is contained a proviso obliging the said John Dicas, under his
hand and seal, to describe and ascertain the nature of the said Invention, and
in what manner the same is to be performed, and cause the same to be
enrolled in His Majesty's High Court of Chancery within four callender
months after the date of the said recited Letters Patent, as in and by the
same (relation being thereunto had) may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, the said
John Dicas doth hereby declare that his said Invention of a New Method of
Constructing the Hydrometer, and also a Sliding Rule adapted thereto,
whereby the real Strength and Comparative Value of Spirituous Liquors,
Malt Worts, and Wash for Fermentation may be exactly ascertained, is
described in the following manner (that is to say):-

page_text: To construct the hydrometer is to have upon the stem thereof ten divisions,
marked 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, beginning at the bottom, and going up
to the top. Thirty-six weights, marked 0, 10, 20, 30, to 350, are to be
adjusted so that the ten divisions upon the stem shall be equal to the difference
between each of them, and where No. O is applyed upon the top of the hydro-
meter, it shall cause it to float in the water to 0 upon the stem; and when the
hydrometer is put into the strongest spirits of wine, the weight 350 shall sink
it to 10 upon the stem. A line of numbers, from 0 to 360, is formed there-
from, and laid down upon one part of the sliding rule, opposite to which is
placed the different strengths of the spirits, and the rule is graduated so as to
shew, by means of a scale thereon, adapted to the thermometer, the just
strength in any degree of heat. The application is by putting the instrument in
the liquor, and trying which of the weights will float it to some of the divisions
on the stem, add the number of that division to that of the weight on the top
and opposite the same; upon the rule will be found the true strength, having
previously fixed the slide so that the index thereon shall be opposite the degree
of heat which the thermometer stands at when placed in the liquor. In like
manner is the strengths of worts and wash to be found, by a larger weight
being fixed at the bottom of the hydrometer, and adjusted so that with the
weight 350 on the top it shall sink to 10 in the stem in water, and No. 0
applyed on the top shall sink it to 0 only in the strongest wort or wash; from
these a similar line of numbers to be laid upon the rule, and opposite to them
the strengths, as before. This hydrometer may be constructed with any
number of divisions upon the stile or stem, placed in the manner described, or
the reverse, beginning with 0 at the top, and carrying it to 10 at the bottom,
and also with any number of weights at pleasure, numbered in the manner
mentioned, or the reverse, provided the rule is figured accordingly, or it may
be constructed with weights applyed to the bottom instead of the top.
In witness whereof, the said John Dicas hath hereunto set his hand and
seal, the Thirteenth day of October, in the twentieth year of the reign
of our Sovereign Lord George the Third, by the grace of God, of
Great Britain, France, and Ireland King, Defender of the Faith,
and so forth, and in the year of our Lord One thousand seven hundred
and eighty.

page_text: AND BE IT REMEMBRED, that on the same Thirteenth day of October,
in the year above mentioned, the said John Dicas came before our said
Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stampt according
to the tenor of the Statute made in the sixth year of the reign of King
William and Queen Mary of England, and so forth.
Inrolled the Twenty-fourth day of October, in the year above mentioned.