The stamp with the name 'Autoplan'
Even collectors of Dutch postmark impressions look up in surprise when they hear the term 'autoplan'. And yet, this type of stamp has existed in the Netherlands for more than eighty years. Even though the stamp had only a short lifespan.
The stamp books housed in the Museum of Communication in The Hague contain two impressions of this typical stamp: one from The Hague and one from Utrecht. But let us first see what has been published about this.

Included with the article was a black-and-white image of an impression of the Rotterdam stamp. Only the year 1931 is clearly recognizable.
The report of the existence of three stamps was based on impressions, such as the one above. It was striking, however, that the Rotterdam impressions were often applied 'across' the postal items. It was also striking that the stamp from The Hague had crosses, while the other two did not. Then the continuation in the Monthly Magazine of March 1931:
The Executive Board of the PTT announces:
A trial is being conducted with the stamps referred to in your letter dated January 30, 1931, as they are equipped with a handle with a detachable coupling, which facilitates easier stamping and a clearer impression on shipments that are not entirely flat. The minor deviations observed by you compared to the stamps otherwise in use can, of course, be disregarded for this trial. No decision can be made at this time regarding the introduction of multiple stamps with detachable handles. They are in trial use in Amsterdam, The Hague (temporarily out of service due to a defect), Rotterdam, and Utrecht. For a trial with a few of these stamps, which were manufactured in Paris, it is not deemed necessary to provide them with a stamp number. It thus turned out to be a trial. The denouement came in October 1936. The following was stated in the PTT Newsletter of July 16, 1936: In 1930, a trial was conducted with the so-called “autoplan” date stamps. These were stamps of French invention, the main characteristic of which was that the stamp head was not fixed, but attached to the handle by a loose coupling. The advantage of this was intended to be that, whether the handle was in a purely vertical or an oblique position, the head would always rest flush on the piece to be stamped, so that a perfect impression should be obtained under all circumstances. Moreover, no prior practice would be required to acquire the necessary skill, and anyone could obtain proper impressions with this stamp. A prototype 's Gravenhage stamp, which differed entirely from the date stamps in use, was produced by the manufacturer. The hour indication was placed before the date, while even minutes were indicated, adjustable in increments of 5. The hour indication changed automatically by means of a button, while the other characters had to be adjusted simply by hand. Before this could be done, a pawl had to be pressed first, with which the characters were held in place. The diameter measured 33 mm. This stamp was not put into use.
A second copy was produced, also for The Hague, of the same size and with the same date as the standard hand-wheel stamps. This stamp was put into trial use in July 1930.
The results made it desirable to extend the trial to Amsterdam, Rotterdam, and Utrecht as well, which was commenced in January 1931. However, the extended trial did not reveal that these stamps were preferable to the date stamps in use, so there was no reason to proceed with the introduction of these French stamps. Of the stamps used in the trial, those for Utrecht and The Hague were taken out of service in 1932 due to a defect; those for Amsterdam and Rotterdam had already met this fate earlier.
Thus, after a short lifespan of only about two years, an experiment with these French stamps came to an end. Impressions from The Hague are the most common. I have seen fewer impressions from Rotterdam and Amsterdam. And never from Utrecht. Do you have an impression of the Utrecht autoplan stamp in your collection? Please let me know!

You can see a postal item with the "Autoplan" test stamp from Utrecht here:
http://www.willempasterkamp.nl/index.php?page=shop.product_details&flypage=flypage_simple.tpl&product_id=13373&category_id=34&option=com_virtuemart&Itemid=1
Netherlands Philately Volume 22/3 contains a short article about these stamps, including a description of a 's Gravenhage Autoplan stamp that is still present in the Museum for Communication in The Hague.
Visit http://asnp1975.com and click on “Back Issues”, which leads to the full article in Vol. 22/3, starting on page 71.
In the upcoming Sheraton & Peel #68 auction (November 30), a postcard from 1931 is being offered under lot number 6515, featuring a beautiful impression of the rare Autoplan stamp from Utrecht. https://filatelist.com
Image: https://www.filatelist.com/original6/6515.html