04-Apr-2020 23:42 by 10 Comments

Compdating - Chat xxx free greek

Adapted for nonprofit, educational purposes from The Harvard University Collection of Historical Scientific Instruments   Figure 5. Adapted for nonprofit, educational purposes from Museum Boerhaave   Abraham was born on the 3rd of May, 1736, in Amsterdam, Netherlands.

A report on the exposition, from the Minister of the Interior, stated that “the excellence of the microscopical objects (of Ypelaar is) known throughout Europe”. Although Ypelaar sought to expand his customer base, he was still targeting a small, niche market: those wealthy enough to engage in microscopy. Documents of the 1808 Exposition list 24 objects for 8 Florins, and a set of 13 objects on the biology of the lacewing fly for 25 Florins.

by Brian Stevenson last updated December, 2016 Abraham Ypelaar is best remembered for his high-quality circular microscope “slides”, made of ivory or bone, with glass covers.

The preparations vary between 1 and 2 cm in diameter.

The Fourth Anglo-Dutch War broke out in 1780, lasting until 1784.

The war severely damaged the Dutch economy, and crippled Ypelaar’s business.

His trade had taught him delicate motor skills, and he soon produced quality mounts that overshadowed those of other preparers.

Until the early 1780s, slide-making was simply a hobby for Ypelaar.

Ypelaar’s use of glass covers, rather than mica, can help discriminate between those preparations that were and were not made by him.

The thickness of the glasses range between 0.2 and 0.7 mm, with a slight curve indicative of production from glass blown into a large, thin bulb.

He was one of the first professional preparers of specimens for the microscope, starting a business in the 1780s.

Some of his larger sets included elongated ebony or brass holders for the circular preparations, facilitating easy viewing on any microscope stage. The set is accompanied by a handwritten list of the specimens, stamped with "A Ypelaar" (see Figure 6).

He later claimed that after selling his preparations for more than 20 years, he still had much of the material he collected during his youth. His parents, Hubertus and Anna Loman Sas, died when Martin was young.