58 Memoir of the late Francis Baily, Esq.^ F.R,S.i S^c. 



I shall by no means go into any minute analysis of the ad- 

 mirable " Report" to the Council of this Society, which con- 

 tains his account of the construction of our standard scale, its 

 comparison with the parliamentary standard, and its most 

 authentic existing representatives — and with the French metre, 

 as we have it represented in this country by two platina metres, 

 in the possession of the Royal Society ; or the means taken to 

 secure it from loss, by the formation of carefully compared 

 copies, two of which have been sent abroad, and two retained 

 in England. Suffice it to say, that the delicacy of the means 

 employed, the minuteness of the precautions used, and the 

 multiplicity of the comparisons, surpassed everything of the 

 kind which had ever before been done in this country. This 

 Report, too, is valuable in another way. Under the modest 

 title of ' A Short History of the Standard Measures of this 

 Country,' it presents a summary of the subject so complete as 

 almost to obviate the necessity of relerring elsewhere for hi- 

 storical inforination*. 



The immediate result of this useful and most laborious un- 

 dertaking has been to put this Society in possession of, per- 

 haps, the most perfect standard measure and divided scale in 

 existence, in which every division, even to the individual 

 inches, has been micrometrically verified, and their errors as- 

 certained and placed on record. It would almost seem, too, 

 as if a prophetic spirit had actuated the undertaking, and 

 urged it to its completion without any of those delays which 

 so often and proverbially attend the construction and optical 

 examination of delicate instruments. For the comparison of 

 the new scale with the imperial standard yard had hardly been 

 completed six months, when the latter, together with the other 

 original standard by Bird (that of 1758), as well as the imperial 

 standard of weight, were destroyed in the conflagration of the 

 Houses of Parliament in October 1834. Thus the operation 

 in question has been the fortunate means of preserving, to the 

 latest posterity, that unit which has pervaded all our science, 

 almost from the first dawn of exact knowledge. 



The scientific unit is indeed preserved ; but the nation re- 

 mained, and remains up to this moment, without a legal stand- 

 ard either of weight or measure. In the early part of 1838, 

 however, in consequence (as I have been led to understand) 



* Mr. Baily was assisted in the actual comparisons by several Fellows of 

 the Society, among whom the late Lieut. Murphy was conspicuous, an ob- 

 server whose temper and scientific habits peculiarly fitted him for co-ope- 

 rating with Mr. Baily, and whose name would probably have occurred more 

 than once in this memoir but for his untimely death, which took place in 

 the service of Astronomy in a distant region, and was probably the unfor- 

 tunate consequence of over-exertion in its cause. 



