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 3527.78 Concordance on Structural Marks
• MS 1831.43 Five-Year Reconciliation
• MS 5496.14 Principle of Co-Substantial Degradation

  The Principle of Co-Substantial Degradation is a governing doctrine of the Tower's archival practice, holding that the degradation of any ca…