220 Miscellaneous Intelligence. 



3. Orthometer and Pleometer, instruments of Navigation. — 

 Mr. Perkins has applied the mercurial level in an ingenious man- 

 ner to the construction of an instrument, calculated to facilitate 

 the sailing of ships. A horizontal tube is turned up vertically 

 at each end, to the height of about three inches. It is then 

 filled with mercury, so that the metal rises about an inch in the 

 two legs, to each of which a float is fixed, forming one end of 

 a lever, as the index does the other end, which is so adjusted 

 that the two indexes are in the same horizontal line, when the 

 mercury is level on the two legs ; but when the mercury is 

 unequal, then the indexes are one higher and the other lower 

 than the horizontal line. Two instruments of this kind being 

 fixed against the sides of a ship's cabin, one parallel to the keel 

 (called the orthometer,) and the other at right angles to it, (the 

 pleometer,) will shew the angular changes in the position of 

 the ship, occasioned either by the distribution of the cargo, or 

 the impulse of the wind. 



The instrument is suspended by two points, one fixed and 

 the other an adjusting screw; and, that the mercury may not be 

 thrown about by sudden changes of position, a stop-cock is 

 attached to the middle of the horizontal tube, by which its bore 

 or capacity may be diminished in any proportion, and the in- 

 strument made to exhibit the average inclination of the vessel, 

 ■without derangement by sudden heaves. 



When the vessel is at sea, and sailing to most advantage, 

 the adjusting screw is turned till the indexes are in the same 

 line, and this adjustment will ever afterwards indicate the trim 

 of the vessel, as long as no material change takes place in the 

 quantity or disposition of the cargo. — Trans. Soc. Arts, xxxix. 

 127. 



4. Arithmometer. — A French artist, M. Thomas, of Colraar, 

 honorary director of the Phoenix Company, has obtained a 

 brevet of invention (patent,) for a machine. of calculation, to be 

 called the arithmometer. It has been presented to the Society 

 for the encouragement of National Industry, and by it a person 

 unacquainted with figures may be made to perform, with won- 

 derful promptitude, all the rules of arithmetic. The most com- 

 plicated calculations are done as readily and exactly as the 

 most simple ; sums in multipUcation and division of seven or 

 eight figures require no more time than those of two or three. 



5. English Buhr Stones. — Messrs. Bishop and Co., of Nant- 

 y-Moch, near Holywell, in Flintshire, have, within the last two 

 or three years, introduced millstones into use, of English 

 origin, which are equal, and in some cases apparently superior, 

 to the celebrated French buhr. Till this source of millstones 

 was discovered, none could be found that could be substituted 



