1891 Infantry Rangefinder

[FNG61]

Captain W.Poste`s range-finder. Engraved to The Royal Military College of Canada. Dated 1891. Box is 13 x 4.25 x 3. There are no instructions with this and I dont know if anything is missing. I am speculating on the use of this. You look through an eye-piece in the lower section of the computing part of the tool. Part of the view looks forward and then there is a mirror which shows the view to your right. The separate disc also has a vision port with a forward view and a mirror with a left hand view. You and a partner view the same object in front of you (the target likely). When the view of the target in front of you and your partner to your side are visible together, you measure how many yards or paces you are apart. The number is dialed onto the scale controlled by the smalest of the knobs which sends a graduated arm up onto a graduated arc. An angle has been involved in these computations of paces or yards and this is now dialed onto the largest of the knobs (there is a an arc at the bottom of the dial with only a zero and 3 un-numbered lines). As the angle is dialed in the graduated arm will come to rest on the (supposed) correct distance in yards to the target. Havent figured out how the angle is arrived at or if there is a piece that may be missing. Was that a completely confusing description Would like to learn more about this item. Have found nothing by Googling except a few things on Steward the manufacturer.