2M/ Experiments to afierta'in 



inches. 

 The I ft of the preceding obfervations giving - - - - 36,0013 



The 2(1 , . . _ _ . _ 35'9933 



The mean length of Mr. Graham's ftandard becomes _ _ ■ 35>9973 



(§. 38.) From the information in the report of a committee of the houfe of commons, 

 that fat in the year 1758, I learnt that Mr. Bird's parliamentary ftandard had been in the 

 cuftody of fome of its officers, but of whom nobody knew : however, under the authority 

 of the fpeaker, who was fo good as to furnifti me with a room in his houfe, to make the 

 coKiparifons ,ln, I at laft difcovered this valuable original in the very fafe keeping of Arthur 

 Benfon, efq. clerk of the journals and papers, and which, I believe, had never feen the light 

 for five-and- thirty years before. It is a brafs rod or bar, about 39 inches long, and i inch 



fquare, inclofcdin a mahogany frame, infcribed " ftandard ^^0 1758;" at each extremity of 



Geo. 2d. 



it is a gold pin, of about t'tj inch in diameter, with a central point, and thefe points are 

 diftant = 36 inches. It bears, however, no diyifions ; but there was found with it, iij 

 another box, a fcale divided into 36 inches, with brafs cocks at the extremities, for the pur- 

 pofe of fizing or gauging other fcalcs or rules by. Befides thefe, I found another ftandard, 

 iaCze, and in all refpefts, fimilar to the laft, infcribed 1760, having been made for another 

 committee, that fat jn that year ; this elfo was accompanied with a fimilar divided fcale of 36 

 inches. 



Thefe bars belng-t-oo thick to be conveniently placed under the microfcopes of my inftru- 

 ment, the interval of 36 ftandard inches was laid down on my fcale with a beam-compafs, 

 two fine points made, and, compared with Troughton's divifions, was = 36,00023 inches ; 

 the thermometer bein^ at 64°. I then examined the other ftandard, marked " ftandard, 

 )76o," and found it to agree exadly with that of J758 j at leaft it did not djfFer from it 

 more than ,0002 inch *. 



(§. 2,c).) I was now to examine the old ftandards kept in the exchequer : thefe Mr. 

 Charles Ellis, deputy x;hamberlain of the tally court at the receipt of the exchequer, was fo 

 good as to fupply me with ; viz. the ftandard yard of the 30th of Eliz. 1588, and alfo the 

 ftandard ell of the fame. date. Thefe are what have been conftantly ufed, and are indeed the 

 only ones now in ufe, for fizing meafures of length f . They are made of brafs, about 0,6 

 inch fquare, and arc very rudely divided indeed, into halves, quarters, eighths, and fix- 

 teenths ; the lines being two or three hundredths of an inch broad, and not all of them drawn 

 fquare, or at right angles to the fides of the bar, fo that no accuracy could poffibly be ex- 

 pefted from fuch meafures. However, the middle point of thefe tranfverfc lines, between 

 the fides of the bar, was taken as the intended original divifitjn ; and thefe divifions, fuch as 



* Thefe quantities then being fo fmall, I fliall confider them as Wholly infenfitile ; and fliall fay, tha-t Mr. 



Bird's parliamentary ftandards of 3 feet exaftly correfpond with Mr. Troughton's fcale. 



f There was alfo a ftandard yard of Henry VII. but of very rude workmanfliip indeed ; new quite laid 



ky, and at what time laft ufed, no information remains : but of this morehcrcafier^ 



they 



