MDMD2: Mr. Bird

[Dave Monroe]

"Despite what Re-assurances you might have had from Mr. Bird ..." (M&D, Ch. 
2, p. 12)

"... and of course the Sector by your Mr. Bird ..." (M&D, Ch. 2, p. 13)

>From Silvio Bedini, "The Transit in the Tower: English Astronomical
Instruments in Colonial America," Annals of Science 54 (1997): pp.
161-96 ...

"Bird, who had become the mechanical coadjutator of the Astronomer Royal, 
the Revd James Bradley, was recognized in the scientific world
as one of the eighteenth century's foremost English makers of precision 
instruments.  Born in Bishop Auckland in the county of Durham, Bird was 
preparing for a career as a cloth-weaver when he happened to notice the 
irregular division of clock dials in a clockmaker's shop.  Turning his 
attention to the art, he became an expert in dividing clock dials, and after 
arriving in London in about 1740, established his own shop for dividing and 
engraving dials.  The instrument-maker Jonathan Sisson employed him for 
dividing mathematical instruments, during which time Bird attracted the 
attention of George Graham, who trained him in instrument-making, and whose 
work he eventually surpassed.  After receiving instruction from Graham, he 
again worked for Sisson before establishing his own shop at 'At the Sea 
Quadrant' in Court Gardens." (pp. 172-3)

>From Edwin Danson, Drawing the Line: How Mason and Dixon Surveyed the
Most Famous Border in America (New York: John Wiley & Sons, 2001), Ch.
6, "Mr. Bird's Contrivances," pp. 60-70 ...

"John Bird (1709-1776) had his instrument workshop at the sign of The Sea 
Quadrant in Court Gardens, a small square at the end of a narrow alley 
leading off the Strand.  In the cramped building, whose roof timbers shook 
whenever the nearby Saint Clement Danes rang, Bird had become famous for 
making the finest scientific instruments.  As a young man he had been 
apprenticed to Jonathan Sisson and had also received instruction from the 
celebrated clock and instrument maker George Graham.... invented the 
revolutionary slow-motion tangent screw, a device that enabled readings of a 
fraction of a second [of a degree] to be made." (pp. 61-2)

"... on sea trials in 1757 ... Captain (later Admiral) John Campbell aboard 
the Royal George, the same vessel that twenty-five years later suffered a 
spectacular capsize immortalized by the poet William Cowper ... used an 
invention ... called a reflecting circle, to measure angular distances; he 
found the instrument next to useless and reverted to his Hadley pattern 
quadrant.  At the end of the voyage, Campbell suggested to Dr. [James] 
Bradley [the third Astronomer Royal (1673-1762)] a refinement to the 
quadrant, one where the effective measuring arc was extended from 90 degrees 
to 120 degrees.  Bradley arranged for John Bird to build the new instrument, 
which had a
radius of eighteen inches, and thus was born the first sextant, a seafarer's 
instrument that remains to this day a mandatory navigation
aid on all ships." (p. 37-8)

"The instruments for the transit of Venus observations included a
12-inch Hadley quadrant made by John Bird ..." (p. 54)

I think this might be what Pynchon is referring to as "the Sector by your 
Mr. Bird," perhaps (or perhaps not ..) confusing it with the more noteworthy 
six-foot-radius zenith sector (...) Bird provided for the Line survey (see, 
e.g., Danson, Drawing the Line, pp. 62-3).  So Pynchon 1, Danson 1 so far?  
But do see also ...

Hellmann, C. Doris.  "John Bird (1709-1776): Mathematical
   Instrument-Maker in the Strand."  Isis 17 (1932): 127-53.

Mason and Dixon's T.O.V. expedition is only mentioned briefly at p. 138, and 
no light is shed on what instruments of Bird's M & D might ultimately have 
taken to the Cape with them, but Hellmann's essay should prove invaluable 
once we get to the Line ...

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