Identify This # 2      

Hello,
I have purchased a large drafting set with some unusual items that I am not familiar with.

The two items of interest are shown at the front two corners of the set. I would also like to know how the  " little wheels" are used.

Update 28th December 2017 - The item shown in the front hand corner is used for drawing dotted lines.

More information and photos are shown under the heading " Drawing Instruments" on the Menu.
I would appreciate any information or comment on the object.
Thank you

Identify This # 1            (Scroll down for #2)

Hello,
I am trying to find out information on this object.
There is no broad arrow stamped on the instrument.
The leather sheath would indicate that it would be used in the field and the thread at the top obviously indicates an attachment like a compass or similar. The leather of the sheath appears to indicate that the object is over 75 yo.
The item looks like a modern day version of a wooden “Jacob’s Staff” which was used in colonial times for surveying.

I would appreciate any information or comment on the item.
Thank you