Chronometers by the ‘proximity of Iron Bodies. 385 
on a circular plate of iron twelve inches in diameter, fully con- 
firmed the conjecture ; such a plate, at the distance of about 
fifteen inches, producing a retardation, in one instance, of more 
than 4" per day, and in another of about 3". 
In his former experiments, also, Mr Barlow suggested the 
idea of estimating, at all times, the effect of the guns, &c. on the 
compass, by introducing such a plate of iron as the above, in a 
situation where its power and effect should be equal to the com- 
bined actions of all the iron of the vessel ; and we are happy to 
learn, by the return of H. M. S. Leven, that these experi- 
ments have, throughout the voyage of sixteen months, given the 
most satisfactory results. The same plan is now proposed by 
him for ascertaining the ship rates of the chronometers before 
they go on board, by simply taking their rates on a certain si- 
tuation, and at a proper distance from such a plate of iron. 
Should this experiment turn out equally satisfactory with the 
above, Mr Barlow will have had the good fortune, first, to have 
discovered a highly interesting scientific fact ; and, secondly , to 
have found its immediate application to the removal of two of 
the most serious impediments to the perfection of practical na- 
vigation. 
Art. XXIII.— Proceedings of the Royal Society of Edin- 
burgh. (Continued from Vol. IV. p. 425.) 
March 19. 1821. D r DuNCANj^mor read a paper 44 On the 
Distribution of the Muscular Fibres of the Ventricles of the 
Heart,” illustrated by Casts and Drawings. 
At the same meeting there was read 44 A Description of a 
New and Universal Balance,” by Dr Dyce of Aberdeen. The 
instrument itself was exhibited to the Society. 
A paper 44 On Electro-Magnetism,” by Mr John Murray, 
Lecturer on Chemistry, w r as read. 
April 2. The following Gentlemen were elected Ordinary 
Members of the Society 4 
Sir Charles Giesecke. Robert Hamilton, M. D. 
R. K. Greville, Esq. 
A paper by Dr Berry was read, entitled, 44 Observations on 
the Method of Sinking Wells at Madras ” 
