Stone-age laboratory

[Shpaget]

1 hour ago, wumpus said:

iron age requires fireproof gloves

Could you elaborate on that?

Sure, a decent pair of heat resistant gloves makes working with hot iron a lot easier, but I don't see it as a requirement.

Leather gloves provide sufficient protection from short heat exposure, and for longer exposure, double up on the layers and add some wool in between. If not enough, make them wet.

Recently I was hardening some steel and had to resort to a coal barbecue to get the thing hot enough (the propane torch I had wasn't getting it hot enough). Since I don't have a proper pair of long blacksmiths tongs I had to use regular pliers. The fire was very hot for my arms so I dunked them elbow deep into a bucket of water and had no problem getting the bright red hot piece of steel out of the fire. I was wearing regular cheap pair of leather gloves you can find on any construction site to protect my hands, but my arms were completely exposed.

Sure, this is not the same as molten iron, but I don't see why would making some gloves from heavy leather be such a problem.

[Zeiss Ikon]

20 hours ago, K^2 said:

I would argue that you are describing a loupe, not a microscope. But distinction isn't relevant to the discussion beyond the name.

Loupes rarely if ever exceed 20x.  There's a van Leeuwenhooke microscope in a museum in Netherlands (one of his later ones, using a simple glass bead for a lens -- but that change was to prevent evaporation, more than for any optical advantage) that's good for 600x.  It's easy to get to 200x with a water drop, and with a little work you can make water drop or glycerin lenses good for 300x or higher.  Magnification enough to see blood cells and zooplankton is a huge step from a 20x loupe, and it's one that could have been taken in Neolithic times.  Add this to the Baghdad battery, the Antikythera computer, and Heron of Alexandria's command of steam and air pressure, and it seems if there'd been communication to match the inventiveness, modern times could have started in the first or second century of the Common Era.  What the Egyptians, Persians, Greeks and Romans mostly lacked was the printing press.

[K^2]

2 hours ago, Zeiss Ikon said:

Loupes rarely if ever exceed 20x.

A magnification device consisting of a single lens acting as both the objective and the ocular and located a fixed distance from subject is called a loupe. This is what you are describing.

Fact that modern loupes are typically designed for comfort, rather than extreme magnification, is a separate discussion. If you have access to good lenses, it's much easier to build a compact microscope that will produce greater magnification at greater image quality than any loupe. Hence, nobody builds loupes for such extreme magnification anymore.

[kerbiloid]

Happily, van Leeuwenhooke didn't know he did all that wrong.