706 FHXLOSOPHICAL TKANSACTION8. [aNNO 1743. 



Standards of 8 and 4 ounces, taken together, outweighed the Royal Society's 

 single Troy pound weight, by 1 grains and -i-th, at a like medium. 



At the Mint in the Tower of London, their standard weights are only a pile 

 of Troy hollow weights, from 256 ounces, down to the l6th part of one ounce, 

 without any penny or grain weights. The larger of these weights, as low as the 

 8 ounce weight, are marked with a. r. crowned, and inscribed primo maii, a® 

 DNi. 1707, a° REGNi vi°. The 4 and the 1 ounce weights are only marked 

 A. R. crowned, without the date; and the less have only the Exchequer seal, and 

 the rose and crown, being the mark of his Majesty's mint, as all the larger 

 ones have also. And here it was found by Mr. Joseph Harris, one of the 

 assay-masters of the mint, with a very curious balance of his own, fixed in a 

 glass lantern, and which he was well assured might in such circumstances be 

 depended on to less than half a grain ; and with the addition of so many penny 

 jmd grain weights belonging to bis office as were necessary : that 



The Royal Society's whole Troy pound weight weighed, at a medium, less than 

 the 8 ounces and 4 ounces of these standards, taken together, by 2 grains and 

 iths. 



That the Royal Society's Avoirdupois pound weighed in Troy weight, by these 

 standards, 14 ounces 11 penny weight l6 grains and -l-ths ; or 700O.87 grains. 



That the Royal Society's pile of ]6 ounces Troy, was lighter than l6 ounces 

 of these standard weights, by 4 grains and ^ths. 



And lastly. That the Royal Society's 8 ounces and 4 ounces together, taken 

 from their pile, weighed lighter than their single Troy pound weight, by ^ths 

 of a grain. 



An Instrument for Reducing a Dislocated Shoulder ; invented by Mr. John Freke, 

 Surgeon of St. Bartholomew's Hospital, and F. R. S. N°470, p. 556. 



Mr. F.'s object in the present communication, is to show within how small a 

 compass the whole power which can be made use of, in reducing a dislocated 

 shoulder, may be contracted. If a machine for this purpose be not portable, it 

 matters but little to an afflicted patient 10 miles off, how good an instrument is 

 out of his reach. 



This machine, fig. 2, pi. 20, which consists of 2 boxes a, joined at the ends 

 by 1 hinges, contains, when folded together, every thing that can possibly be 

 wanted in the operation beforementioned ; and it may so easily be made use of, 

 without the assistance of any other operator than the surgeon employed, that 

 he ventures to affirm, a patient may be set down, the instrument applied, and 

 the shoulder reduced, in 1 minute, ordinarily speaking. 



The length of this instrument, when shut up, is 1 foot 8 inches, its breadth 

 9 inches and thickness 3 inches and a quarter. When it is opened, it is kept 



