3 holdings are shelved on this floor. A shared floor records where volumes sit and nothing about what any of them says; these are neighbours, not relations.

• MS 7826.51 Bureau of Weights and Consciences
• MS 9109.04 Revision of the Ninth Annex
• MS 9108.29 Validation

  Validation is the Tower-wide practice of certifying that a door is internally consistent: that it opens onto what it claims to open onto, th…