Thread: Japanese Optics - Type 98 Light (weight) Theodolite

[BOUGAINVILLE]

Here is one of my Type 98 Light (weight) Theodolites. Dated November 1941 and was manufactured by the Tokyo Optical Company, Ltd., or what has been known for the past several decades as Topcon.

This was used in laying artillery lines and surveying etc. It has the receptacle to take the optical grid illumination lamp which is shown in the last photo. This Lamp was used on many of the optical instruments such as the Type 93 Battery Commanders Scope.

There are two variations of this theodolite. One has 3 lugs on the front lens to receive the Type 98 Light (weight) Theodolite Periscope. This variation will be shown in the next post.

The complete set of accessories are shown. The small bar is for the special screws that secure the spirit levels.

The screw on bakelite eye piece is broken and I wonder if anyone can point me in the right direction for two replacements. One for each of my units.

Also am looking for a tripod for the Type 98. If anyone has one for sale please contact me.

 

[Gunnerwho?]

What's the source for saying that 'Theodolites' were used for 'laying artillery lines'? Theodolites are instruments used for survey, both topographic (ie map making) and artillery (providing accurate orientation and fixation to a point). Theos are characterised by their precision, eg scales to 5 seconds or 0.1 mil or similar. However, artillery is oriented by a different and less precise instrument, called a Director in Australia or Aiming Circle in US. Artillery sights precision is usually to something in the order of 5 minutes or 1 mil and directors have the same precision. And yes I'm well aware that meteor theodolites are different.

 

[BOUGAINVILLE]

What's the source for saying that 'Theodolites' were used for 'laying artillery lines'? Theodolites are instruments used for survey, both topographic (ie map making) and artillery (providing accurate orientation and fixation to a point). Theos are characterised by their precision, eg scales to 5 seconds or 0.1 mil or similar. However, artillery is oriented by a different and less precise instrument, called a Director in Australia or Aiming Circle in US. Artillery sights precision is usually to something in the order of 5 minutes or 1 mil and directors have the same precision. And yes I'm well aware that meteor theodolites are different.

Many thanks for the info. I pulled that piece of info from I think some listing on the net but the person must've layman and meant accurate orientation and fixation to a point. It is excellent having your indepth information.

Cheers,
BOUGAINVILLE