84 



NOTES AND QUERIES. 



[No. 117. 



Hertford two days before, viz. on the 23rd of 

 May. 



In answer to Hertfordiensis, who asks for 

 information as to its site, I quote a passage from 

 Herbert's edition of Ames's Typographical Anti- 

 quities, under the description of the work of 

 Bartholomeus, printed by Wynkyn de Worde. 

 Herbert says, vol. i. p. 201. : — 



" I have been informed that this mill was where 

 Seel, or Seal Mill is now, at the end of Hertford town, 

 towards Stevenage ; and that an adjoining meadow is 

 still called Paper-mill Mead, This Seel Mill, so de- 

 nominated from the adjoining hamlet, was erected in 

 the year 1 700 ; and is noted for being the first that 

 made the finest flour, known by the name of Hertford- 

 shire White. It stands upon the river Bean, in the 

 middle of three acres of meadow land, called Paper- 

 mill Mead, so denominated in the charter of King 

 Charles I. to the town of Hertford for the fishery of a 

 certain part of that river. Hence, perhaps, some have 

 thought it was at Stevenage, but there is no water for 

 a mill at or even near tiiat place." 



The French authorities are particularly unhappy 

 on the subject of the introduction of the art of 

 paper-making in England. According to the 

 Dictionnaire de la Conversation, " la premiere 

 manufacture, etablie a Oertford en Angleterre, 

 est de 1588 ;" while the Encyclopedie des Gens du 

 Monde asserts that " la premiere patererie de 

 chiffons qu'eu notre pays fut etablie en 1312 ; 

 celle d'Angleterre en 1388." A. Grayan. 



THE PENDULUM DEMONSTRATION. 



(Vol. iv., pp. 129. 177. 235. 277.) 



Since my last communication on this subject 

 (Vol. iv., p. 235.) I have been engaged in examin- 

 ing the theory, and the experiments connected 

 with it, somewhat more closely ; and, in the mean- 

 while, I abstain from replyini; to the last observa- 

 tions of A. E. B. (Vol.iv., p. 277.) 



A. E. B. says it was " uncourteous" in me to 

 call the theory which he put forward his theory. 

 I beg pardon for the offence. I intended by the 

 expression merely to indicate the particular theory 

 which he advocated. I believe its author is 

 M. Chesles. The theory in question is : 



" That the variation of the pendulum's plane is due 

 to the excess of velocity with which one extremity of 

 the line of oscillation may be affected more than the 

 other." 



I ventured to pronounce this to be untenable, 

 and begged A. E. B. to " reduce it to paper." 

 Upon this he remarked : 



" H. C. K. is surely not so unphilosophical as to 

 imagine that a theory, to be true, must be palpable to 

 the senses. If the element of increase exist at all, 

 however imperceptible in a single oscillation, repetition 

 of effect must eventually make it observable. But I 

 shall even gratify H. C. K., and inform him, that the 



difference in linear circumference between two such 

 parallels in the latitude of London, would be about 

 50 feet; so that the northern end of a 10 feet rod, 

 placed horizontally in the meridian, would travel less 

 by that number of feet in twenty-four hours, than the 

 southern end. This, so far from being inadequate, is 

 greatly in excess of the alleged apparent motion in the 

 place of the pendulum's vibration." 



I think, if A. E. B. will reconsider this opinion, 

 he will find that, so far from being "greatly in 

 excess," it is inadequate to account for the amount 

 of apparent motion of the plane of the pendulum. 

 For the onward motion of the plane of a 2 sec. pen- 

 dulum, describing a circle of 10 feet diameter in 

 twenty-four hours, amounts to '0087 inch at each 

 beat ; 50 feet will be the difference in the distance 

 the two extremities of the arc of vibration will, 

 travel in twenty-four hours ; that is, '0138 inch in 

 2 seconds of time : but this is for a difference of 

 10 feet; therefore, for 5 feet, the distance from 

 the centre, it is '0069 inch ; whereas the arc de- 

 scribed is -0087 inch, which is absurd. 



However, there is another equally fatal objec- 

 tion to this theory, founded on experiment ; to 

 make which objection good, I will not merely 

 adduce the result of my own, but that of certain 

 experiments carried out at Paris, which place the 

 matter beyond a doubt. In the Pantheon, at 

 Paris, there is a pendulum of the length of 230 

 feet, by means of which experiments can be made- 

 under the most favourable conditions possible as- 

 regards suspension, exclusion of currents of air,. 

 &c. &c. While witnessing the trials that were 

 being made, a relation of mine requested that the 

 pendulum might be set to oscillate east and west ; 

 and the result was, that the arc described after an 

 interval of ten minutes, was the same as that de- 

 scribed when the pendulum was oscillating north 

 and south. 



To return to the original theory. I stated 

 formerly that I had no faith in the experiments- 

 which had been published. I now repeat that I 

 believe all the experiments that have been made, 

 with the view of showing the rotation of the earth,^ 

 and the independence of the pendulum of that 

 rotation, are inconclusive; and for the following 

 reason, the impossibility of obtaining perfect sus- 

 pension. Even in a still atmosphere, and with a 

 pendulum formed of the rigid rod and a " bob," 

 the axis of both of which shall be precisely in a 

 line with the point of suspension ; yet, until sus- 

 pension can be effected on a mathematical point, 

 and all torsion and local attraction got rid of, the 

 pendulum will not continue to swing in the same 

 plane for many consecutive beats ; because the 

 slightest disturbance will cause the " bob" to de- 

 scribe an ellipse ; and, by a well-known law, the 

 major axis of that ellipse will go on advancing in 

 the direction of the revolution. This advance is 

 by regular intervals ; and my belief, founded on 



