TRANSACTIONS OF THE SECTIONS. 3 
On the Parallax of a Lyre. By the Rev. Dr. Rozinson. 
_ The observations of the late Dr. Brinkley, he observed, with an 
eight-feet circle, indicated a parallax of about 1’ for a Lyre; but 
__ Mr. Pond, with the Greenwich mural, appeared,to obtain contradict- 
ory results. His observations seemed so satisfactory, that the Royal 
Society considered the question as completely decided, and rewarded 
him with their medal. It is true that the Society afterwards seemed 
to retract this opinion, by awarding the same honour to Brinkley 
_ himself; but the impression remained on the public mind. Dr, Ro- 
‘binson should not have noticed this, but that he observed, in some 
late addresses, that this opinion was sanctioned by the illustrious names 
of Airy and Peacock. In reducing the Greenwich observations for 
_ the nutation, he had many of a Lyre, and, selecting those which were 
_ near the maxima and minima of parallax, he obtained the following 
-yalues of the constant of parallax :— 
_ Parallaxes of a Lyre resulting from Mr. Pond's Observations. 
Parallax. No. of Observations, 
Summer ...... PBUS5 os. 6. —O°07 .......- 
Winter ...... MSUT eet 6770) Fa ee 33 
Winter ...... 1819°0 ..... UN=wY Ta const rasena iO 
Summer ...... 1819°5 ...... aS teosse stheee (Oe 
Winter ...... TB20'O" ss 5s = er Reet 18 
Winter ...... 1822°0 ...... —3°BD cecccccevecs 16 
Winter ...... 1827-0 ...... Sm AE tc ecateiece 21 
r Summer ...... WS D cnpaces 1 ly A Pa 70 
Winter ...... 1828°0 ...... —O18 ............ 30 
Summer ...... ie eee 4 a (ED Tei te wes Oe 
Winter ...... TSAO: westee MOS. oss phy aches 26 
Summer ...... Sires teas +0°99 ......-..08. 22 
Winter ...... T8300) 3.225. is aan ee 9 
Summer ....., OG ep eee +0°90 2... .c cee eee 22 
Winter ...... {SSO HOMO] cde ceseneses 23 
Summer ...... gol eercs +1°30 ... 29 
Combining and expressing by d?z the error of nutation, and by dm 
the error of prop. motion. 
4 1812 
; 1818 > ... par=—1'28—0'8 d’n+0°3dm,. ...... 78 obs. 
1822 
tee =—O°95 .....000- aU Ao) SANS 55 
| oe re =—O0AZ ......... —02 91 
1828 reat (60.2 0) Bannan me U2 PRE ee 82 
1829 eames ES | ae et —O0'3 ......00. 70 
BAG). agers cde, SOO les aps ses oa LG castes sax 31 
ila haa = +0°68 +0°05d’2—0°3 ......44 52 
‘in which it is supposed that d’x=—0°31; dm.=+0:07, assuming 
_ Bessel’s proper motion to be true. 
These results obviously may give any parallax, and, therefore, as far 
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