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[[page number]] 119)
A BRASS & STEEL BAR RIVETTED TOGETHER, & PREVENT THE IRREGULARITY OF THE BALANCE SPRING ARISING FROM HEAT.
less advantage, when the vibrations are larger.
4.  To remedy the last defect, Mr. Harrison uses a Bar compounded of two thin plates of Brass and Steel, about two inches in length, riveted in in several places together, fastened at one end, and having two pins at the other, between which the Balance Spring passes.  If this bar be streight in temperate weather (brass changing its length by heat more than steel) the brass side becomes convex when it is heated; and the steel side when it is cold: And thus the pins lay hold of a different part of the spring in different degrees of heat, and lengthen or shorten it, as the Regulator does in a common Watch.

REMARKS ON THESE REMEDIES & HOW FAR THEY MAY BE IMITATED.
   The two first of these Improvements, and good Workman, who should be permitted to view and take to pieces Mr. Harrisons Watch, and be acquainted with the tools he uses, and the directions he has given, could without doubt, exactly imitate.  He could also make the palates of the shape proposed; but for the other improvements, Mr. Harison has given no rules.  He says, that he adjusted those parts by repeated trials, and that he knows no other method.  This seems to require patience and perseverance; but with these qualifications other workmen need not despair of success equal to Mr. Harrison's.  There is no reason to suspect that Mr. Harrison has concealed from [[inserted]] us [[inserted]] any part of his art.
If our opinion of the excellence and usefulness of this Machine be asked, I must fairly own, that nothing but experience can determine the value of it with certainty; however, I think it my duty to declare to the board the best judgment I can form.

STRICTURES THEREON.
   The first of Mr. Harrison's alterations is, I believe, an improvement, but not very considerable.  Probably if the other defects in common watches could be removed, the changes in the [[strikethrough]] motion [[/strikethrough]] Force of the main spring would not occasion such errors, as would make them useless at sea.  

   The next alteration seems to be of great importance.  I suppose that it contributes more the the exactness of the watch, that all the other changes put together.  But it is attended with some [[strikethrough]] ill convenience [[/strikethrough]] inconvenience The watch is liable to be disordered, and even stopped by almost any sudden motion, and, when stopped, does not move again of itself.  But as it has gone two voyages without any such accident, it may seem, that his danger at see is not so considerable.
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