# No autograph observing book from Ptolemy survives; later manuscripts are the public file

Date: 150

## The fact

St Andrews MacTutor and Britannica state that the public file is later manuscripts and printed editions, not a surviving Mouseion observing diary. Opacity of a famous observer is the path: later states cannot audit a log that is not there.

It is one event.

## Context

High confidence on the gap. This forbids a fake 127 CE ISO observation Fact as if it were a civil-registry row.

Ptolemy’s documented role is bounded by other offices and collaborators named in the sources below. Sharing a field with them is not a reason to drop a documented act, and it is not a reason to assign later consequences done in the name after death.

Conventional floruit is the mid-2nd century CE in Roman Alexandria.

Named person as heading of the dated public instrument. Later editors, museums, printers, or offices share publication. Complex where later carriers are the surviving public file.

## Evidence and sources

MacTutor — Claudius Ptolemy and Britannica — Ptolemy independently describe this instrument.

Official or archival record: MacTutor — Claudius Ptolemy (https://mathshistory.st-andrews.ac.uk/Biographies/Ptolemy/; University of St Andrews).

## Significance

Do not invent an Alexandrian logbook. Do write the gap.

## What is established and what is not

Established as a dated public record of this instrument.

What would change the picture: a contradictory original with a different date or name, or a measured series that can be argued, with lag and alternatives, as a consequence of this instrument rather than of later institutions.

What would change the picture: a contradictory original with a different date or name, or a measured series that can be argued, with lag and alternatives, as a consequence of this instrument rather than of later institutions.

The date is the date of this instrument, not a licence to back-date every later harm or benefit.

Established here: a sourced, dated public instrument with a named contribution by Ptolemy.

They are not a public rating.

The driver `personal-data-protection` is attached because the mechanism named in Significance follows from this instrument, not because a standing list of welfare headings needed another tick. Ptolemy did not file a later UNESCO form, a later Loeb colophon, or a later museum label as a personal act. A portrait or conventional bust is not this mechanism. Allegation, reconstruction, and established occurrence stay distinct. Driver `personal-data-protection` is attached because the Significance sentence names a mechanism from No autograph observing book from Ptolemy survives; later manuscripts are the public file at 0150-02-01, not because a standing driver list needed coverage. Official page: https://mathshistory.st-andrews.ac.uk/Biographies/Ptolemy/. Independent page: https://www.britannica.com/biography/Ptolemy.

## People

- Ptolemy: https://factrail.ai/people/ptolemy

## Drivers

- Personal-Data Protection: https://factrail.ai/drivers/personal-data-protection

## Sources

- https://www.britannica.com/biography/Ptolemy
- https://mathshistory.st-andrews.ac.uk/Biographies/Ptolemy/

## Methodology

https://factrail.ai/methodology

Canonical: https://factrail.ai/facts/pto-no-observing-log