Wildrik Botjes was a goldsmith and watchmaker working in Nieuwe Pekela, about 20 miles southeast of the city of Groningen in the Netherlands. He was interested in astronomy, and was fascinated with the idea of representing the motions of bodies in the solar system by a mechanical device. As a hobby he constructed the miniature planetarium which is now displayed in North Hall at Calvin College. The construction required fifteen years, and was completed in 1868. Upon completion, he transferred it to his nephew and began work on another planetarium.

Wildrik's nephew, Botje Hinderikus Bos (see photo), was also a watchmaker and an avid amateur astronomer. He brought the planetarium with him when he immigrated to America in 1896. The arrival in Kalamazoo, Michigan, of the wonderful machine was reported in the August 4, 1896 issue of the Kalamazoo Morning News. The planetarium ran continuously throughout his life, with one interruption: the main spring was broken during a storm at sea on the passage to America. Botje repaired the damage himself with his watchmaker skills. Botje in turn handed the planetarium down to his son, George (Tjaart) Bos.

Although George also had an interest in astronomy, he passed the planetarium on to his brother, Henry B. (Hinderikus) Bos (see photo), when he left Kalamazoo. Henry B., a skilled woodworker, kept it in running order, and submitted it to an exhibition in Kalamazoo in 1926, in which it won a first prize ribbon. At some point before this the surface was repainted, with the labels rewritten in English.

When Henry B. passed away in 1968, the planetarium passed to his son, Henry A. Bos. It ceased running soon thereafter. Henry and his wife Bertha (see photo) donated the planetarium to Calvin College in 1989, with the understanding that it would be restored to operating condition and placed on display. It was officially accepted by Calvin College and restored to working order by Prof. Clarence Menninga. It was placed on display on May 18, 1992, and has been kept in operating condition since that time. The donation of the planetarium to Calvin College was reported in a 1992 issue of the Grand Rapids Press.

	Day of the week
	Botjes planetarium home page
	Mechanism and restoration