Sheet of invalidated half penny Mt Cook green postage stamps

These sheets of half penny pictorial stamps are significant because they have been invalidated for use as test coils in stamp vending machines.

London-born New Zealander Robert Dickie invented the world’s first practical stamp-vending machine. Dickie arrived in Aotearoa with his parents in 1888 and joined the Wellington Post Office in 1891. At the time, clerks sold stamps by tearing them from large sheets, and Dickie thought that was a waste of time. He became obsessed with the idea of a coin-operated stamp-dispensing machine, which could be set up in public places and make getting stamps more efficient and convenient. Dickie’s mechanical engineering skills were limited so he partnered with photographer and mechanical draftsman John Henry Brown, and they patented their first machine in 1904. 

The problem with the Dickie-Brown machine was that in order to work, the machine needed strips of stamps rolled into coils. The Government Printers advised that they could not print coils of stamps locally and if done overseas the cost would be prohibitively expensive, so Dickie and Brown bought sheets of stamps and made the strips themselves. The Post and Telegraph Department agreed to sell them imperforate sheets at face value so they could test their machine, and they devised a way of perforating the coiled stamps with two 2mm holes between each stamp.

The first Dickie-Brown vending machine was trialled at the Wellington Post Office in 1905 and received enthusiastically. Further trials in 1906 improved the mechanics of the machine, and Dickie had successful trials in the United Kingdom, United States and Australia. The partnership with Brown eventually dissolved, and coin-operated stamp vending machines became known by the generic name ‘Dickie Machines’, at least in New Zealand.

One of the major issues with stamp vending machines which still had to be overcome had to do with the standard paper and perforations used in the making of stamps. If the coils were too weak to withstand the vending mechanism and the roll tore, the machine would be out of action until someone could come to fix it. For his first trials Dickie used imperforate sheets which he punched in such a way that it did not excessively weaken the roll, but that required special printings or large stocks of imperforate sheets.

After the successful 1905-06 trials, Dickie turned his attention to designing a ‘small pin’ vending machine that could use normally perforated sheets for conversion to coils. He also developed equipment to automate the production of coils, and needed a supply of sheets he could use for testing. The Post and Telegraph department provided sheets of invalidated stamps for this purpose.
 
Dickie sold the New Zealand patent for his stamp vending machines to the Post and Telegraph Department in 1918 but stayed on as their ‘Stamp Vending Machine Expert’. He continued to refine the mechanisms throughout his career, and for more than half a century Dickie’s machines were in use around the world.

References:

• Kundin, Stanley J. 2009. The Vending & Affixing Machine Coils of New Zealand. [Wellington]: Royal Philatelic Society of New Zealand.
• Reid, Donald. 2007. ‘Robert J Dickie: Champion of Automation’. NZ Edge website, 24 June. https://www.nzedge.com/legends/robert-j-dickie/