328 Analysis of Scientific Books. 



depends, in the opinion of the author, upon the equality of the 

 muscles of the tympanum. 



4. Corrections applied to the great Meridional Arc, extending from 

 latitude 8° 9' 3S".39, to latitude 18° 3' 23'.64, to reduce it to the par- 

 liamentary standard. By Lt. Col. W. Lanibton, F.R.S., <§-c. 



It appears from Capt. Rater's results that Col. Lambton's 

 standard scale requires a multiplier of —,000018 to make it agree 

 with Bird's standard; and that Ramsden's bar, used in the tri- 

 gonometrical survey of Great Britain, requires the multiplier 

 +,00007. That is to say, with respect to a measurement on the 

 meridian the degree depending on Col. Lambton's brass scale must 

 be multiplied by ,000018, and the product subtracted from the 

 measure given by the scale, to reduce it to the parliamentary 

 standard. And the degree depending on Ramsden's bar, must be 

 multiplied by ,00007, and the product added to the measure 

 given by the bar, to reduce it to the standard measure. The au- 

 thor then proceeds to correct the different sections of his arc by 

 the above factors. 



5. On the Changes which have taken place in the Declination of some of 

 the principal fixed Stars. By John Pond, Esq., Astronomer Royal. 



C. Appendix to the preceding Paper — by the same. 



The mural circle having been pronounced by Mr. Troughton as 

 perfect as when first erected, Mr. Pond resumes his observations, 

 but finds the discordances which had so much perplexed him still 

 continue. To place, however, the accuracy of the instrument 

 beyond all doubt, he contrives an apparatus, which enables him to 

 observe most of the stars by reflection, from the surface of Mercury ; 

 the result is, that several stars (and particularly those which had 

 exhibited the greatest anomalies) thus observed, have within a 

 fraction of a second, the same places assigned to them, as direct 

 measurement from the pole had previously given them. Ten stars 

 situated near the zenith, give the horizontal point of the instrument 

 123° 30' 29".54, whilst Sirius places at 123° 30' 29".47, differing 

 only seven hundredths of a second. Hence, neither flexure of the 

 telescope, or change of figure in the instrument, need be appre- 

 hended. The stars in which a very great deviation toward the 

 South is found, are Capella, Procyon, and Sirius. 



In the appendix to the above paper, Mr. Pond, finding that 

 recent observations confirm the results hinted at in his last paper, 

 investigates minutely how far the discordances between his pre- 

 sent catalogue, and that of Bradley of 1756, and his own of 1813, 

 may be accounted for, by instrumental error, or erroneous obser- 

 vation. The consequence of the inquiry is, that the present devia- 



