Many Hilger Watts theodolites allow you to "plunge" the telescope (rotate it 180 degrees in the vertical plane) to check collimation. The manual describes how to release the vertical circle clamp safely without unbalancing the instrument, preventing internal damage.
The original Hilger Watts wooden carrying case is part of the instrument. The manual details how the tripod legs should be placed inside the case first , then the theodolite body—reverse of what most people assume. hilger watts theodolite manual