Return the Julian Date corresponding to Besselian Date 1900.0.

   None.

   The function returns the Julian Date corresponding to Besselian
   date 1900.0.

   None.

   The function returns 2415020.31352, the Julian Date corresponding
   to Besselian Date 1900.0 as reported by Lieske [1].

   None.

   Lieske [1] defines a mapping from Julian Ephemeris Date 
   to Besselian:

      BE = 1900. + (JED - 2415020.31352)/365.242198781

   The inverse mapping being:

      JED = (BE - 1900.)*365.242198781 + 2415020.31352

   The following code fragment illustrates the use of b1900_c.

      /.
      Convert Julian Date to UTC seconds past the reference
      epoch (B1900).
      ./

      spref = ( jd - b1900_c() ) * spd_c();

   None.

   Error free.

   None.

   W.L. Taber      (JPL)
   I.M. Underwood  (JPL)

   [1] Jay Lieske, ``Precession Matrix Based on IAU (1976)
       System of Astronomical Constants,'' Astron. Astrophys.
       73, 282-284 (1979).

   -CSPICE Version 1.1.0, 01-SEP-2005 (EDW)

       Added journal reference and associated citations.

   -CSPICE Version 1.0.1, 08-FEB-1998 (EDW)

       Corrected and clarified header entries.

   -CSPICE Version 1.0.0, 25-OCT-1997 (EDW)

   besselian date 1900.0