Often in war films one can observe how a soldier is observing from the trench of an enemy through a tricky device. The “eyes” of this device rise above the parapet, while the observer is located below, inaccessible to the bullets of enemy snipers. The name of this telescope is the periscope. Who invented it and is it possible to make a periscope with your own hands?
Invention
The word "periscope" in free translation from Old Hellenic sounds something like "I look around." It has been known about the prototype of this device since the 15th century, and it was invented, as often happens, not at all for what it is now used for - observing the enemy during military operations.
Christian pilgrims made the simplest periscope with their own hands, fixing two fragments of a mirror on a stick at a 45 ° angle.
This simple device was used in order to be able to see over the heads of the crowd at the festival in Aachen. For the time being, the invention was given the modest role of a funny toy, but already in the 17th century the situation changed.
Application
Humanity is fighting the whole history of its existence. Moreover, the jump in the development of deadly devices that kill at a distance occurred almost instantly from the point of view of world history. Lances and crossbows were replaced by bows and crossbows. Arrows began to reach the enemy at unprecedented distances, the power of the shot and the accuracy of the shooters were constantly growing.
It is not surprising that handicraftsmen soon wondered how to make a periscope that allows you to observe the movements of the enemy, while remaining invulnerable. In the 17th century, the periscope began to be used in the siege of fortresses to monitor the besiegers, without risking being hit by an arrow or a crossbow bolt.
And in the middle of the 19th century, when in many states mass attempts were made to build submarines, the periscope almost immediately became their integral part. His device was perfectly suited for tracking ordinary surface ships. Moreover, the observation could be conducted covertly, without surfacing, and this is the most important requirement in the conduct of hostilities.
Homemade simple periscope
It is not at all difficult to make the simplest periscope with your own hands. In order to acquire a means of covert surveillance, you need to stock up on two small mirrors. You can get tidy cosmetic mirrors, or you can cut two rectangular mirrors with a glass cutter (who owns such skills).
The next thing you need is a case. Here fantasy is not limited by any framework. Any oblong item from a sufficiently hard, but amenable to material. Even a box, narrow and long, made from sweets, will do.
A periscope drawing is shown in the figure. The transformation of the box from monpansier to espionage occurs as follows:
- At the bottom and top of the case, inspection holes are cut out - from opposite sides, as shown in the diagram.
- Inside the case, mirrors are mounted at an angle of 45 ° to the vertical axis. Mounting the mirrors should provide the possibility of their adjustment, it will need to be done later and to ensure that the objects of observation are visible in the periscope, and not the inside of the device.
One of the options for making a periscope with adjustable mirrors is shown in an additional diagram. The mirror is glued to the base of multilayer plywood, along its edges at 3 points there are adjustment bolts. To keep the mirror in a stable position, a compressed spring is inserted between the mounting plate and the base.
We complicate the design
The simplest home-made periscope will not allow to consider in detail an object located in the distance. It would be tempting to combine the capabilities of a periscope and a telescope. A periscope manufacturing option with the function of approximating distant objects is shown in the diagram.
The basis is the same simplest periscope, but two new elements are added to it: a lens and an eyepiece taken from a finished telescope. Having a little understanding of the basics of optics, having familiarized yourself with the manufacturing options for home-made telescopes-refractors, you can choose lenses for the lens yourself.
Assembling the periscope with your own hands based on the details of the finished telescope, it is necessary to ensure strict compliance with one rule (circled in red). The total distance between the lens and the eyepiece should be exactly the same as it was with the telescope, taken as a basis.
It is worth taking care of the possibility of adjusting (leveling) the focal length to adjust the sharpness of the device. In the diagram, the eyepiece is inserted into a special ocular tube.