NavList:

A while back I discovered the Indian Astronomical Ephemeris is available as a free download from the Indian government:

http://packolkata.gov.in/indian-astronomical-ephemeris.php

It produces the same data as you'd find in the Astronomical Almanac, but the way the information is formatted in the text feels like it was sealed in amber for the past 40 years or so.  For example, the tables of rise and set times are shown directly for nothern latitudes only, with a separate table of corrections used to calculate times for southern latitudes.  Duration of twilight is tabulated rather than specific start and end times.  If you've thumbed through an older almanac this should sound familiar to you.

Other differences from the Astronomical Almanac are a little more subtle but seem geared more towards saving the reader some calculation.  For example, semidiameters of planets are tabulated directly in the IAE while the AsA expects the reader to multiply two numbers together.  The position of the moon is tabulated twice-daily instead of daily;  it's not hourly, but it does help with interpolation (where the AsA apparently doesn't even publish lunar polynomials online any more).

Linear interpolation isn't accurate enough for most data, even to navigational accuracy, but the tables of interpolation coefficients are a little more robust than in the AsA.  Multiplication is still involved, but for navigational accuracy you could probably make the interpolation table from HO 229 work for you.

But speaking of tables, the appendix is straight from 1899.  Tables include converting back and forth between sidereal and mean solar time; back and forth between arc and time; hours/minutes/seconds to decimals; refraction tables, with corrections for temperature and pressure; amplitudes; augmentation of the moon's semidiameter; and even a small trig function table, tabulated for arc and time.

Overall I'm left with the impression that the IAE feels a lot like the almanacs that maritime navigators were expected to deal with 70+ years ago, books that tried to cater to both navigators and to people who could rely on instruments on tripods. 

I thought this could be interersting for those looking for a "steampunk" experience in navigation.  But if nothing else it's an opportunity to snag some archaic tables that aren't third-generation photographic reproductions.