What were they thinking?

Found at Anglo-Catholic Ruminations.

In accordance with the structure of each church and legitimate local customs, the Most Blessed Sacrament should be reserved in a tabernacle in a part of the church that is truly noble, prominent, readily visible, beautifully decorated, and suitable for prayer.

The one tabernacle should be immovable, be made of solid and inviolable material that is not transparent, and be locked in such a way that the danger of profanation is prevented to the greatest extent possible. Moreover, it is appropriate that, before it is put into liturgical use, it be blessed according to the rite described in the Roman Ritual. — General Instruction of the Roman Missal (GIRM) 314.