William Ladd (1815-85) is listed working at this particular address from 1846-56. The accessories, including a syphon gauge, a Magdeburg sphere, a glass bulb with valve and a hand pump, also carry Ladd’s name.
This model is one that was first made much earlier. The twin cylinder vacuum pump was developed by Francis Hawksbee (1660-1713) in c.1705 based on a pump first made by Denis Papin (1642-1712) in 1674.
This Victorian demonstration model comes in its oak travelling case which has helped preserve it in excellent original condition. It is priced at £5450 from Hansord in Lincoln.