Evidence toward the nature of Spinoza’s Lathe(s)

Writing an email today to an interested party I found myself running over the evidence that Spinoza used either a hand driven lens-grinding lathe, or one of the springpole variety, such as the Hevelius lathe (Selenographia, 1647). It seemed best to briefly summarize them hear, as though the evidence is scant, it is not non-existent. [...]

Spinoza’s Grinding Lathe: An Extended Hypothesis

A Proposed Homologue to Spinoza’s Grinding Lathe It has been revealed by some digging into the record by Stan Verdult that indeed the lathe that occupies the Rijnsburg Spinoza museum is not of the sort Spinoza would have used (though it may give us a sense of the size of his lathe). [Written about here: The [...]

Spinoza: Not As Abused As Is Said

Two Kinds of Disparagment Found In the Huygens Letters I am looking at the references to Spinoza made by Christiaan Huygens, coming to them with the expectation that they would reveal a general disparagement of the man, either in terms of his optical knowledge, or in terms of his person, for these letters have been characterized as proof of [...]

A Method of Grinding Small, Spherical Lenses: Spinoza

Van Gutschoven’s Design for Grinding Small Lenses: Letter No. 1147 We have in a letter written to Christiaan Huygens by G. van Gutshoven, descriptions and diagrams of the essential processes for grinding small spherical lenses, as they were likely shared by most contemporaries of the age. The letter is surely a response to a request [...]

Huygens’s Comments On Spinoza’s Theory of the Microscope to His Brother

[Opening Comment: I post below an extensive excerpt from a significant letter by the hand of Christiaan Huygens. It is has been cited by biographers for two main reasons. For one, the initial sentence is stated as evidence for Huygens' regard for apparently an argument or demonstration that Spinoza had put to him in Voorburg, one possibly with some conjunction with Johannes Hudde: "It [...]

Simple or Compound: Spinoza’s Microscopes

Smaller Objective Lenses Produce Finer Representations A very suggestive clue to the kinds of microscopes Spinoza may have produced is Christiaan Huygens’ admission to his brother Constantijn in a May 11 1667 letter that Spinoza was right in one regard, that smaller objective lenses do produce finer images. This has been cited by Wim Klever [...]

Spinoza’s Brilliant Neighbor, The Huygens Estate: Hofwijck

Christiaan Huygens drawing of Hofwijck, where Spinoza would have visited To add to the picture of the quiet Huygens family estate at Voorburg we have a drawing of it by the hand of Christiaan Huygens himself (undated). This brings a certain vividness to any imagined visit by Spinoza in the summer of 1665 [thought about here: [...]

Huygens’s Collaboration with Instrument Makers

Evidence Towards Huygens’s tendency to appropriate or minimize the design contributions of others In considering the remote possibility that the rapid improvements that Christiaan Huygens made in the single lens microscope in the years 1677 and 1678 may have reflected the designs of Spinoza’s own microscopes likely purchased by the brothers, [discussed here: Did the Huygenses “buy” [...]

Spinoza and Diamond Polishing?

What was Spinoza’s Relationship to the Gem and Diamond Trade I post here a portion of a hard to find book, in the interest of establishing a baseline of information for others. Because this site has involved a variety of hypotheses on the kinds of influences Spinoza may have had, all should be sketched out [...]

The Simple Microscope in the Hands of Van Leeuwenhoek and Huygens

Spinoza’s Microscopology: a prospective comparison of context It strikes me that there is a subtle, yet important contrast between the single lens microscope that Christiaan Huygens ended up offering by the Fall of 1678 and the design which was consistently used by Van Leeuwenhoek, a contrast that points up a branching out of conception of the relationship between instrument [...]