The technical significance.

The Verbruggens were experimenting with a new type of horizontal boring machine. The first one was installed in The Hague in 1758. Before the advent of boring machines, guns were cast with the barrel already in place. It was difficult to keep the casting mould of the barrel perfectly centered during the casting process. As a result these types of guns were not very acurate and needed to be overdesigned to compensate for the deviation of the positioning of the barrel in the gun.

The model of the horizontal boring machine the Verbruggens developed and installed in The Hague in 1758 is today on display at the National Military Museum in Amersfoort, the Netherlands.

 

Guns for a horizontal boring machine on the other hand were cast solid. The barrel was later bored perfectly centered into the gun. This was accomplished by turning the gun instead of the bore during the process. The gun was turned by horses and the boring could take several days.

The machine installed in The Hague had to work with a furnace with insufficient capacity. This led to a relatively high number of impurities in the cast. Competitive founders were against the new method in spite of the higher accuracy and lighter guns it produced. They mounted an investigation into the quality of Verbruggens guns and eventually got him expelled as Master Founder in The Hague.

Excerpt from the Resolution of the Raade van Staate der Verenigde Nederlanden, showing impurities in two Verbruggen guns, October 19, 1770.

Verbruggen moved with his son and two daughters to Greenwich, UK. Here he became master founder of the Royal Arsenal. He was allowed to fully refurbish the foundry and install his new Horizontal Boring Machine in 1778. It proved a much more reliable production method.

The Royal Foundry in Woolwhich, with in the background left, The Verbruggen house built for the family Verbruggen. Both still exist today.

The horizontal boring machine was in fact the first industrial sized Lathe installed in the UK. The Lathe (The Mother of All Machines) is essential for the production of sophisticated machines with pistons, cylinders, crankshafts etc. Henry Maudselay, the later inventor of many improvements to the Lathe (e.g. automatic turning of screw thread) worked as an apprentice at the Foundry of Verbruggen.

The Lathe is an essential element in the ensuing Industrial Revolution that took place in the UK.

The Industrial Size Lathe installed by Verbruggen in Woolwhich in 1784.

 

The principle of a horizontal boring machine had been invented earlier by the swiss Founder De Maritz. The design was sold earlier in the 18th century (approximately 1735) to the French government. Since the invention was treated as a military secret, it was not available to civilians. That may have been one of the reasons that the Lathe did not develop until later in France.

Design for De Maritz’ Horizontal Boring Machine 1735.