PERISCOPE, an optical device that makes it possible to examine objects located in horizontal planes that do not coincide with the horizontal plane of the observer’s eye. Used on submarines to monitor the sea surface when the boat is submerged, in ground army- for safe and inconspicuous observation of the enemy from protected points, in technology - for examining inaccessible internal parts of products. In its simplest form, a periscope consists of a vertical pipe (Fig. 1) with two mirrors S 1 and S 2 inclined at an angle of 45° or prisms with total internal reflection, located parallel to each other at different ends of the pipe and facing each other with their reflective surfaces . However, the periscope reflective system can be designed in different ways. A system of two parallel mirrors (Fig. 2a) gives a direct image, the right and left sides of which are identical to the corresponding sides of the observed object.
A system of two perpendicular mirrors (Fig. 2b) gives a reverse image, and since it is viewed by an observer standing with his back to the object, the right and left sides change their places. Inverting the image and shifting the sides is easy to achieve by placing a refractive prism in the system, but the need to observe with your back to the object, and therefore difficulty in orientation, remains, and therefore the second system is less suitable. The disadvantages of the periscope shown in Fig. 1 and used in trench warfare, are a small angle of view α (about 10-12°) and a small aperture ratio, which forces us to limit ourselves to a length of no more than 1000 mm with a relatively large pipe diameter - up to 330 mm. Therefore, in a periscope, the reflective system is usually associated with a lens system. This is achieved by attaching one or two telescopes to the reflective system of the periscope. Moreover, since a conventional astronomical tube gives a reverse image with displaced sides, the combination of perpendicular mirrors with such a tube will give a direct image with correctly positioned sides. The disadvantage of such a system is the position of the observer with his back to the subject, as mentioned above.
Attaching an astronomical tube to a system of parallel mirrors is also impractical, since the image will turn out upside down, with the sides facing away. Therefore, a periscope usually combines a system of parallel mirrors and an earthly telescope, which gives a direct image. However, installing two astronomical tubes after two inversions will also give a direct image, which is why it is also used in a periscope. In this case, the pipes are positioned with lenses facing each other. The refractive system of a periscope does not present any special features compared to a telescope, however, the choice of one or another combination of telescopes (or rather lenses), their number and focal length determined by the required viewing angle and periscope aperture. In the best periscopes, image brightness is reduced by ≈30%, depending on the system and type of lens.
Since the clarity of the image also depends on the color of objects, improved visibility is also achieved by using color filters. In the simplest form of a periscope (Fig. 3), the upper lens O 1 gives a real image of the object at point B 1, refracting the rays reflected by the prism P 1. The collecting lens U also creates at point B 2 a real image of the object, which is reflected by the prism P 2 and viewed through the eyepiece O 2 by the eye of the observer. Tubes typically use achromatic lenses and take steps to eliminate other aberration distortions. By installing two telescopes one after the other, operating similarly to the one described above, it is possible to increase the distance between the prisms without compromising the aperture of the periscope and its field of view. The simplest periscope this type is shown in Fig. 4. Already the first periscopes of this type provided a field of view of 45° and a magnification of 1.6 with an optical length of 5 m and a pipe diameter of 150 mm.
Because observing with one eye is tiring, periscopes were proposed that provide an image on frosted glass, however, this image significantly lost in clarity, and therefore the use of frosted glass in periscopes did not become widespread.
The next stage in the development of the idea of periscopes was attempts to eliminate the need to rotate the periscope tube when viewing the horizon 360°. This was achieved by connecting several (up to 8) periscopes on one pipe; the corresponding part of the horizon was examined through each of the eyepieces, and the observer had to walk around the pipe. This kind of multiplier periscopes did not give the whole picture as a whole, and therefore omniscopes were proposed that give the entire horizon in the form of a ring picture by replacing the lens with a spherical refractive surface. This kind of devices, being characterized by considerable complexity, did not provide an increase in the vertical field of view, which interfered with the observation of aircraft, and distorted the image, and therefore fell out of use. More successful was the strengthening of the optical system in the inner tube, which could rotate inside the outer one independently of the latter (Fig. 5).
This kind of panoramic periscope, or kleptoscope, requires some additional optical device. The light beam penetrating the periscope head through the ball glass lid H, which protects the device from water ingress and does not play an optical role, is distributed through the optical system P 1, B 1, B 2, etc., which is fixed in the inner tube J. The latter rotates using a cylindrical gear transmission, shown at the bottom of the device with handle G, regardless of the outer casing M. In this case, the image falling on the lens B 3, refracted by the prism P 2 and viewed by the eyepiece, will rotate around the light axis of the eyepiece. To avoid this inside inner pipe a quadrangular prism D is strengthened, rotating around vertical axis using planetary gears K 1, K 2, K 3 at half speed and straightening the image.
The optical essence of the device is clear from Fig. 6, showing how rotating the prism rotates the image at twice the speed. An increase in the field of view in the vertical direction from 30° in a conventional periscope to 90° is achieved in an zenith periscope by installing a prism in the objective part of the device, rotating about a horizontal axis, regardless of the rotation of the entire upper part about a vertical axis to view the horizon. The optical part of a periscope of this type is shown in Fig. 7.
Periscopes are used on submarines for two purposes: observation and control of torpedo fire. Observation may consist of simple orientation in the environment and a more careful examination of individual objects. For observation, objects should be visible in life size. At the same time, it has been practically established that for accurate reproduction with monocular observation of objects that are usually observed binocularly with the naked eye, the magnification of the device must be increased. more than 1.
Currently, all submarine periscopes have a magnification of 1.35-1.50 for easy orientation. For a thorough examination of individual objects, magnification should be used. more, with the maximum possible illumination. Currently, an increase of X 6 is used. Thus. Periscopes have a double requirement regarding the magnification of the device. This requirement is satisfied in bifocal periscopes, the optical part of the lens of which is shown in Fig. 8.
Changing the magnification is achieved by rotating the system 180°, while the lens O 1 and lens K 1 do not move. For greater magnification, use the system V' 1, P" 2, V' 2; for smaller magnification, use the system V 1, P 1, V 2. Appearance The lower part of the anti-aircraft bifocal periscope is shown in Fig. 9.
The described design for changing magnification is not the only one. More simply, the same goal is achieved by removing excess lenses from the optical axis of the device, mounted in a frame that can be rotated around the axis at will. The latter is designed vertically or horizontally. For direction finding of objects, determining their distance, course, speed and for controlling torpedo firing, periscopes are equipped special devices. In fig. 10 and 11 shown Bottom part periscope and the observed field of view for a periscope equipped with a vertical base rangefinder.
In fig. Figure 12 shows the field of view of the periscope for determining the distance and heading angle using the alignment principle.
In fig. 13 shows the lower part of a periscope equipped with a photographic camera, and FIG. 14 - lower part of the periscope with a device for controlling torpedo firing.
When the periscope head moves, it causes waves on the surface of the sea, which make it possible to establish the presence of a submarine. To reduce visibility, the head of the periscope is made as small in diameter as possible, which reduces the periscope's aperture and requires overcoming significant optical difficulties. Usually a narrow one is only suitable top part pipes, gradually expanding it downwards. The best modern periscopes, with a tube length of more than 10 m and a diameter of 180 mm, have an upper part about 1 m long with a diameter of only 45 mm. However, experience has now established that the discovery of a submarine is achieved not by detecting the periscope head itself, but by the visibility of its trace on the surface of the sea, which persists for a long time. Therefore, at present, the periscope is protruded above the surface of the sea periodically for a few seconds, necessary for making observations, and is now hidden until it reappears after a certain period of time. The wave formation caused in this case is significantly closer to the usual disturbance of sea water.
The difference in temperature in the pipe and in environment in combination with air humidity inside the periscope leads to fogging of the optical system, to eliminate which devices are installed for drying the periscope. An air tube is installed inside the periscope, led into the upper part of the pipe and coming out at the bottom of the periscope. On the other side of the latter, a hole is made from which air is sucked out of the periscope and enters a filter charged with calcium chloride (Fig. 15), after which it is pumped into the upper part of the periscope by an air pump through the inner pipe.
Periscope tubes must meet special requirements for strength and rigidity in order to avoid damage to the optical system; in addition, their material should not affect the magnetic needle, which would disrupt the operation of ship compasses. In addition, the pipes should be especially resistant to corrosion in sea water, because in addition to the destruction of the pipes themselves, the tightness of the connection in the seal through which the periscope extends from the boat’s hull will be disrupted. Finally geometric shape pipes must be particularly accurate, which, if they are long, creates significant difficulties in production. Ordinary material For pipes, low-magnetic stainless nickel steel (Germany) or special bronze - immadium (England) - which has sufficient elasticity and rigidity, is used.
Strengthening the periscope in the hull of a submarine (Fig. 16) causes difficulties, depending both on the need to prevent sea water from getting between the periscope tube and the hull of the boat, and on the vibration of the latter, which interferes with the clarity of the image. The elimination of these difficulties lies in the design of an oil seal that is sufficiently waterproof and at the same time elastic, securely connected to the hull of the boat. The pipes themselves must have devices for quickly raising and lowering them inside the boat hull, which, with the periscope weighing hundreds of kg, leads to mechanical difficulties and the need to install motors 1, which rotate winches 2, 4 (3 - switching on for the middle position, 5 - manual drive, 6, 7 - handles for the clutch mechanism). When the tube is raised or lowered, observation becomes impossible because the eyepiece quickly moves vertically. At the same time, the need for observation is especially great when the boat surfaces. To eliminate this, a special platform for the observer is used, connected to the periscope and moving with it. However, this causes overload of the periscope pipes and the need to allocate a special shaft in the ship’s hull to move the observer. Therefore, a stationary periscope system is more often used, allowing the observer to maintain his position and not interrupt his work while moving the periscope.
This system (Fig. 17) separates the ocular and objective parts of the periscope; the first remains stationary, and the second moves vertically with the pipe. To connect them optically, a tetrahedral prism is installed at the bottom of the pipe, etc. the light beam in the periscope of this design is reflected four times, changing its direction. Since the movement of the tube changes the distance between the lower prism and the eyepiece, the latter intercepts the light beam at various points (depending on the position of the tube), which disrupts the optical unity of the system and leads to the need to include another movable lens that regulates the beam rays according to the position of the pipe.
Typically, submarines have at least two periscopes installed. Initially, this was caused by the desire to have a spare device. Currently, when two periscopes of different designs are required - for observation and attack, the periscope used during the attack is at the same time a spare one in case one of them is damaged, which is important for performing the main task - surveillance. Sometimes, in addition to the indicated periscopes, a third, spare one is installed, used exclusively when both main ones are damaged.
Army periscopes are distinguished by greater simplicity of design compared to naval ones, while at the same time maintaining the main features and improvements of the device. Depending on the purpose, their design is different. A typical trench periscope consists of wooden pipe with two mirrors (Fig. 1). The design of the periscope tube is more complex, including an optical refractive system, but not distinguished by any special dimensions; such a pipe is usually designed on the principle of a panoramic periscope (Fig. 18).
The dugout periscope (Fig. 19) is similar in design to the simplest type of naval periscope and is intended for making observations from shelters.
A mast periscope is used to observe distant objects or in the forest, replacing inconvenient and bulky towers. It reaches a height of 9-26 m and consists of a mast that serves to strengthen the optical system, mounted inside two short pipes large diameter. The eyepiece tube is mounted on a carriage at the bottom of the mast, and the objective tube is mounted on the retractable top of the mast. Thus, in this type there are no intermediate lenses, which, despite a significant magnification (up to x 10), with a low mast position causes a decrease in the latter as the mast extends, with a simultaneous decrease in image clarity. The mast is mounted on a special carriage, which also serves to transport the device, and the mast moves. The carriage is quite stable and only when strong wind requires additional fastening with bends. The periscope is successfully used in technology to inspect holes drilled in long forgings (shafts, gun channels, etc.), to check the absence of cavities, cracks, and other defects. The device consists of a mirror located at an angle of 45° to the axis of the channel, mounted on a special frame and connected to the illuminator. The frame moves inside the channel on a special rod and can rotate around the axis of the channel. The telescopic part is mounted separately and is placed outside the forging under study; it serves not to transmit an image, as in an ordinary periscope, but to better view the field of view captured by the periscope.
A periscope is an optical instrument. It is a telescope that has a system of mirrors, prisms and lenses. Its purpose is to carry out surveillance from a variety of shelters, which include shelters, armored towers, tanks, and submarines.
Historical roots
The periscope dates back to the 1430s, when the inventor Johannes Gutenberg invented a device that made it possible to observe the spectacles at fairs in the city of Aachen (Germany) over the heads of a crowd of people.
The periscope and its structure were described by the scientist Jan Hevelius in his treatises in 1647. He intended to use it in the study and description of the lunar surface. He was also the first to suggest using them for military purposes.
The first periscopes
The first real and functional periscope was patented in 1845 by American inventor Sarah Mather. She managed to seriously improve this device and bring it to practical application in the armed forces. So, during the period civil war in the USA, soldiers attached periscopes to their guns for secretive and safe shooting.
The French inventor and scientist Davy adapted the periscope for the navy in 1854. His device consisted of two mirrors rotated at an angle of 45 degrees, which were placed in a pipe. And the first periscope used was invented by the American Doty during the American Civil War of 1861-1865.
First world war soldiers on both sides also used periscopes various designs for shooting from cover.
During World War II, these devices found widespread use on the battlefield. In addition to submarines, they were used to observe the enemy from shelters and dugouts, as well as on tanks.
Almost since the advent of submarines, periscopes on them have been used for surveillance when the submarine is underwater. This happens at the so-called “periscope depth”.
They are designed to clarify the navigation situation on the sea surface and to detect aircraft. As the submarine begins to dive, the periscope tube is retracted into the submarine's hull.
Design
A classic periscope is a design of three separately located devices and parts:
- Optical tube.
- Lifting device.
- Cabinets with seals.
The most complex design mechanism is the optical system. These are two astronomical tubes combined with lenses. They are equipped with mirror prisms of total internal reflection.
Submarines also have additional devices for the periscope. These include rangefinders, systems for determining heading angles, photo and video cameras, light filters, as well as drying systems.
To establish the distance to a target in a periscope, two types of devices are used - rangefinder reticles and micrometers.
A light filter is indispensable in a periscope. It is located in front of the eyepiece and is divided into three sectors. Each sector represents a certain color of glass.
The camera of the device or another one designed to obtain an image is necessary to establish the facts of hitting targets and recording events on the surface. These devices are installed behind the periscope eyepiece on special brackets.
The periscope tube is hollow; it contains air, which contains a certain amount of water vapor. In order to remove moisture deposited on the lenses, which condenses on them due to temperature changes, a special drying device is used. This procedure is carried out by quickly passing dry air through the pipe. It absorbs accumulated moisture.
On a submarine, a periscope looks like a pipe protruding above the wheelhouse with a “knob” at the end.
Usage tactics
To ensure secrecy, the submarine's periscope is raised from under the water at certain periods of time. These intervals depend on weather conditions, speed and range of observation objects.
The periscope assists the submarine commander in determining the direction (bearing) from the submarine to the target. Allows you to determine the heading angle of the enemy vessel, its characteristics (type, speed, weapons, etc.). Provides information about the moment of the torpedo salvo.
The dimensions of the periscope protruding from under the water, its head part, should be as small as possible. This is necessary to prevent the enemy from recording the location of the submarine.
Enemy aircraft pose a very great danger to submarines. As a result, during submarine crossings, significant attention is paid to monitoring the air situation.
However, to carry out such combined observation, the end part of the periscopes is quite massive, since anti-aircraft observation optics are located there.
Therefore, submarines are equipped with two periscopes, namely a commander’s (attack) and an anti-aircraft periscope. Using the latter, you can monitor not only the air situation, but also the surface of the sea (from the zenith to the horizon).
After the periscope is raised, the air hemisphere is inspected. Observation of the water surface is initially carried out in the bow sector, and then moves to a review of the entire horizon.
To ensure secrecy, including from enemy radar, in the intervals between raising the periscope, the submarine maneuvers at a safe depth.
As a rule, the elevation of a submarine's periscope above sea level ranges from 1 to 1.5 meters. This corresponds to visibility of the horizon at a distance of 21-25 cables (about 4.5 km).
The periscope, as mentioned above, should be above the surface of the sea for as short a period of time as possible. This is especially important for a submarine that begins an attack. Practice shows that it takes a little time, about 10 seconds, to determine the distance and other parameters. Such a time interval for the periscope to be on the surface ensures its complete secrecy, so it is impossible to detect it in such a short period of time.
Traces on the surface of the sea
When the submarine moves, the periscope leaves behind a wake and breakers. It is clearly visible not only in calm conditions, but also in slightly rough seas. The length and nature of the breaker, the size of the wake, are directly dependent on the speed of the submarine.
So, at a speed of 5 knots (about 9 km/h), the length of the periscope trail is about 25 m. The foam trail from it is clearly visible. If the speed of the submarine is 8 knots (about 15 km/h), then the length of the wake is already 40 m, and the breakers are visible at a great distance.
When a submarine moves in a calm state, a pronounced White color breakers and a voluminous foam trail. It remains on the surface even after the device is pulled inside the case.
As a result, before raising it, the submarine commander takes measures to slow down the speed of movement. In order to reduce the visibility of the submarine, the end part is given a streamlined shape. This is easy to notice in the existing periscope photos.
Other disadvantages
The disadvantages of this surveillance device include the following:
- It cannot be used in the dark, or in conditions of poor visibility.
- A periscope looking out of the water can be detected without significant difficulty both visually and with the help of radar equipment of a potential enemy.
- Photos of such a periscope taken by observers - what business card presence of a submarine here.
- With its help, it is impossible to determine the distance to the target with the necessary accuracy. This circumstance reduces the effectiveness of using torpedoes against it. Moreover, the detection range of the periscope leaves much to be desired.
All of the above shortcomings led to the fact that in addition to periscopes, new, advanced surveillance means for submarines appeared. This is primarily a radar and hydroacoustics system.
A periscope is an essential instrument on a submarine. Implementation in technical systems modern submarines, new devices (radar and hydroacoustic) have not reduced its role. They only supplemented its capabilities, making the submarine more “sighted” in poor visibility, in conditions of snow, rain, fog, etc.
A periscope is a device with which you can observe objects outside our field of vision. For complex and precise observations, complex and precise instruments are made. In these cases, periscopes are equipped with a very complex optical system. However, for amateur purposes, you can construct a simple periscope from two pocket mirrors. It will allow you to penetrate the secrets of life of shy birds and other animals.
The proposed design has an important additional advantage: the periscope can be significantly lengthened if the object of interest is hidden behind a high obstacle. Materials needed sold in stationery and haberdashery stores. You will need two sheets of flexible cardboard and two pocket mirrors. The shape of the mirrors does not matter - they can be either round or rectangular. - but definitely the same.
In accordance with the size of the mirrors, glue two tubes about 50 cm long from cardboard or paper, and one of them should be slightly larger diameter so that the tubes fit into each other. (If you have rectangular mirrors, then, naturally, the “holders” in cross-section can be square).
When the glue dries, cut out in the side walls of the tubes, at their ends. sharp knife one hole at a time. Moreover, make the hole through which you will look into the periscope with a diameter of approximately 1 cm. And the hole in the second tube should be the same size as the mirror inserted into it.
Cut a hole in the tube with square section It’s very simple, but if the cross-section is round, it’s more complicated. It is very important to keep in mind that the center of the holes must coincide with the center of the mirrors. Glue sun protection devices to the holes; they make observations much more convenient.
From pieces of cardboard or foam plastic, make two stands with holders for setting the position of the mirrors in the tubes.
After the glue connecting the stands, holders and Mirrors has dried, the finished units of our periscope are inserted into one another. And again, it is necessary to precisely adjust their position in relation to the holes cut in the side walls of the tubes. The mirrors should be at an angle of 45° to the longitudinal axis of the device and direct the observed image as shown in the figure.
Before the final installation of the periscope, one more operation needs to be performed - painting. The internal surfaces of the periscope are painted black, for example, with drawing ink. This improves observation conditions. Paint the outside of the periscope gray or gray-green water-repellent paint. These colors are maximal, they blend well with surrounding objects.
ROMAN KOZAK
Magazine “Technology Horizons for Children” No. 8-85.
PERISCOPE, optical a device that makes it possible to examine objects located in horizontal planes that do not coincide with the horizontal plane of the observer’s eye. It is used on submarines for observing the surface of the sea when the boat is submerged, in the ground army - for safe and discreet observation of the enemy from protected points, in technology - for examining inaccessible internal parts of products. In its simplest form, the P. consists of a vertical pipe (Fig. 1) with two inclined at an angle of 45 degrees. mirrors S1
And S2 or prisms with total internal reflection, located parallel to each other at different ends of the pipe and facing each other with their reflective surfaces. However, the P. reflective system can be designed in different ways. A system of two parallel mirrors (Fig. 2a) gives a direct image, the right and left sides of which are identical to the corresponding sides of the observed object. A system of two perpendicular mirrors (Fig. 26) gives a reverse image, and since it is viewed by an observer standing with his back to the object, the right and left sides change their places. Inverting the image and shifting the sides is easy to achieve by placing a refractive prism in the system, but the need to observe with your back to the object, and therefore difficulty in orientation, remains, and therefore the second system is less suitable. The disadvantages of P. shown in Fig. 1 and used in trench warfare, are a small angle of view a (approx. 10-12 degrees) and a small aperture, which forces us to limit ourselves to a length of no more than 1,000 mm with a relatively large pipe diameter - up to 330 mm. Therefore, in photography, the reflective system is usually associated with a lens system. This is achieved by attaching one or two telescopes to the P. reflective system. At the same time, since ordinary astronomical If the pipe gives a reverse image with its sides moved, then the combination of perpendicular mirrors with such a pipe will give a direct image with the sides correctly positioned. The disadvantage of such a system is the position of the observer with his back to the subject, as mentioned above. Joining astronomical pipes to a system of parallel mirrors is also impractical, since the image will turn out upside down, with the sides facing away. Therefore, in P., a system of parallel mirrors and a terrestrial telescope, which gives a direct image, are usually connected. However, the installation of two astronomical pipes after two inversions will also give a direct image, which is why it is also used in P. The pipes in this case are positioned with lenses facing each other. The refractive system of a telescope does not present any special features in comparison with a telescope, however, the choice of a particular combination of telescopes (or rather lenses), their number and focal length is determined by the required angle of view and aperture ratio of the telescope. In the best telescopes, the brightness of the image is reduced by 30 % depending on the system and type of lenses. Since the clarity of the image also depends on the color of objects, improved visibility is also achieved by using color filters. In the simplest form of a periscope (Fig. 3), the top lens ABOUT1
gives at the point IN1
actual image of an object by refracting rays reflected by a prism P1. Collective lens U creates at point IN2
also the actual image of an object that is reflected by a prism P2 and viewed through the eyepiece O2 the eye of the observer. Tubes typically use achromatic lenses and take steps to eliminate other aberration distortions. By installing two telescopes one after the other, operating similarly to the one described above, it is possible to increase the distance between the prisms without compromising the aperture of the lens and its field of view. The simplest P. of this type is shown in Fig. 4. Already the first P. of this type gave a field of view of 45 degrees. and magnification 1.6 with optical. 5 m long with a pipe diameter of 150 mm. Because observation with one eye is tiring, then P. were proposed that gave an image on frosted glass, but this image significantly lost in clarity, and therefore the use of frosted glass in P. did not become widespread. The next stage in the development of the P. idea was attempts to eliminate the need to rotate the P. pipe when inspecting the horizon at 360R. This was achieved by connecting several (up to 8) P. on one pipe; the corresponding part of the horizon was examined through each of the eyepieces, and the observer had to walk around the pipe. This kind of multiplier photos did not give the whole picture as a whole, and therefore omniscopes were proposed that gave the entire horizon in the form of a ring picture by replacing the lens with a spherical refractive surface. This kind of devices, being characterized by considerable complexity, did not provide an increase in the vertical field of view, which interfered with the observation of aircraft, and distorted the image, and therefore fell out of use. More successful was the strengthening of optical fiber. system in the inner pipe, the edges could rotate inside the outer one regardless of the latter (Fig. 5). 
This kind of panoramic P., or kleptoscopes, require some additional optical technology. devices. The light beam penetrates the P. head through the ball glass cover H1,
protecting the device from water ingress and not playing optical signals. role, distributed via optical fiber. system R1
, IN1,
IN2
etc., the edges are strengthened in the inner pipe J. The latter rotates using a cylindrical. gear train, shown at the bottom of the device with a handle G, regardless of outer casing M. In this case, the image incident on the lens IN3
,
refracted by a prism R2
and viewed by the eyepiece, will rotate around the light axis of the eyepiece. To avoid this, a quadrangular prism is strengthened inside the inner pipe D, rotating about a vertical axis using a planetary gear TO1,
K2, K3
at half speed and straightens the image. 
Optical the essence of the device is clear from Fig. 6, showing how rotating the prism rotates the image at twice the speed. Increase the field of view in the vertical direction from 30 degrees. in ordinary P. up to 90 degrees. is achieved in anti-aircraft photography by installing a prism in the objective part of the device, rotating about a horizontal axis, regardless of the rotation of the entire upper part about a vertical axis to view the horizon. Optical part of a P. of this type is shown in Fig. 7. P. are used on submarines for two purposes: observation and control of torpedo firing. Observation may consist of simple orientation in the environment and a more careful examination of individual objects. For observation, objects should be visible in life size. At the same time, it has been practically established that for accurate reproduction with monocular observation of objects that are usually observed binocularly with the naked eye, the magnification of the device must be increased. more than 1. Currently, all submarines have a magnification of 1.35--1.50 for simple orientation. For a thorough examination of individual objects, magnification should be used. more, with the maximum possible illumination. Currently, the magnification is X 6. Thus. P. is subject to a double requirement regarding the increase in the device. This requirement is satisfied in bifocal lenses, optical. part of the lens is shown in Fig. 8. 
Changing the magnification is achieved by rotating the system 180R, while the lens ABOUT1
and lens K1, n3 are moving. For greater magnification the system is used
for smaller ones - system V1, P2, V2. The appearance of the lower part of the zenith bifocal P. is given in Fig. 9. 
The described design for changing magnification is not the only one. More simply, the same goal is achieved by removing from the optical. the axis of the device of excess lenses fixed in the frame, the edges can be rotated at will around the axis. The latter is designed vertically or horizontally. 
To find direction of objects, determine their distance, course, speed, and to control torpedo firing, the missiles are equipped with special devices. In fig. 10 and 11 show the lower part of the periscope and the observed field of view for the P., equipped with a vertical-base rangefinder. 
In fig. Figure 12 shows the P.'s field of view for determining the distance and heading angle based on the principle of alignment. 
In fig. 13 shows the lower part of the P., equipped with a photographic camera, and FIG. 14—the lower part of the gun with a device for controlling torpedo firing. 
When moving, the P.'s head causes waves on the surface of the sea, which make it possible to establish the presence of a submarine. To reduce visibility, the head part of the P. is made as small in diameter as possible, which reduces the P.'s aperture and requires overcoming significant optical difficulties. difficulties. Usually, only the upper part of the pipe is made narrow, gradually widening it downwards. The best modern pumps with a pipe length greater than 10 m and a diameter of 180 mm
have an upper part approx. 1 m with a diameter of only 45 mm. However, experience has now established that the discovery of a submarine is achieved not by detecting the head of the submarine itself, but by the visibility of its trace on the surface of the sea, which persists for a long time. Therefore, at present, P. is protruded above the surface of the sea periodically for a few seconds, necessary for making observations, and is now hidden until it reappears after a certain period of time. The wave formation caused in this case is significantly closer to the usual disturbance of sea water. Difference t
in the pipe and in the environment, in combination with the humidity of the air inside the P., leads to fogging of the optical fiber. system, to eliminate which devices are installed for drying the P. An air tube is installed inside the P., led into the upper part of the pipe and coming out at the bottom of the P. On the other side of the latter, a hole is made, from which air is sucked out of the P. and enters a filter charged with calcium chloride (Fig. 15), after which it is pumped into the upper part of the periscope by an air pump through the inner pipe. 
P. pipes must meet special requirements for strength and rigidity in order to avoid disruption of optical performance. systems; in addition, their material should not affect the magnetic needle, which would disrupt the operation of ship compasses. In addition, the pipes should be especially resistant to corrosion in sea water, because in addition to the destruction of the pipes themselves, the tightness of the connection in the gland, through which the pipe extends out of the boat hull, will be disrupted. Finally geometric. The shape of the pipes must be particularly precise, which, if they are long, creates significant difficulties in production. The usual material for pipes is low-magnetic stainless nickel steel (Germany) or special bronze-- immadic(England) - having sufficient elasticity and rigidity. 
Strengthening the P. in the hull of a submarine (Fig. 16) causes difficulties, depending both on the need to prevent sea water from getting between the P. pipe and the boat’s hull, and on the vibration of the latter, which disrupts the clarity of the image. The elimination of these difficulties lies in the design of an oil seal that is sufficiently waterproof and at the same time elastic, securely connected to the hull of the boat. The pipes themselves must have devices for quickly raising and lowering them inside the hull of the boat, which, with a weight of hundreds kg leads to mechanical difficulties and the need to install motors 1,
which rotate the winches 2, 4
(3
-- inclusion for the middle position, 5-manual drive, 6, 7
-- handles for the clutch mechanism). When the tube is raised or lowered, observation becomes impossible because the eyepiece quickly moves vertically. At the same time, the need for observation is especially great when the boat surfaces. To eliminate this, a special platform for the observer is used, connected to the P. and moving with it. However, this causes overloading of the P. pipes and the need to allocate a special shaft in the ship’s hull to move the observer. Therefore, a stationary post system is more often used, allowing the observer to maintain his position and not interrupt his work while moving the post. 
This system (Fig. 17) separates the ocular and objective parts of the lens; the first remains stationary, and the second moves vertically with the pipe. For optical their connections at the bottom of the pipe establish a tetrahedral prism, etc. the light beam in the P. of this design is reflected four times, changing its direction. Since the movement of the tube changes the distance between the lower prism and the eyepiece, the latter intercepts the light beam at various points (depending on the position of the tube), which disrupts the optical performance. the unity of the system leads to the need to include another movable lens that regulates the beam of rays according to the position of the pipe. Usually at least two P are installed on submarines. Initially, this was caused by the desire to have a spare device. At present, when two P. of different designs are required for observation and attack, the P. used in the attack is at the same time a reserve in case of damage to one of them, which is important for performing the main task - observation. Sometimes, in addition to the indicated P., a third one is installed, a spare one, used exclusively in case of damage to both main ones. Army P. are distinguished by greater simplicity of design compared to naval ones, while at the same time maintaining the main features and improvements of the device. Depending on the purpose, their design is different. A typical trench P. consists of a wooden pipe with two mirrors (Fig. 1). More complex is the design of the P. pipe, which includes optical. a refractive system, but not distinguished by any special dimensions; such a pipe is usually designed on the principle of a panoramic periscope (Fig. 18). 
The dugout P. (Fig. 19) is similar in design to the naval one of the simplest type and is intended for making observations from shelters. A mast periscope is used to observe distant objects or in the forest, replacing inconvenient and bulky towers. It reaches a height of 9--26 m and consists of a mast that serves to strengthen the optical fiber. system mounted inside two short large diameter pipes. The eyepiece tube is mounted on a carriage at the bottom of the mast, and the objective tube is mounted on the retractable top of the mast. So. Thus, in this type there are no intermediate lenses, which, despite a significant increase (up to x 10) at a low position of the mast, causes a decrease in the latter as the mast extends, with a simultaneous decrease in image clarity. The mast is mounted on a special carriage, which also serves to transport the device, and the mast moves. The carriage is quite stable and only in strong winds requires additional fastening with bends. The periscope is successfully used in technology to inspect holes drilled in long forgings (shafts, gun channels, etc.), to check the absence of cavities, cracks, and other defects. The device consists of a mirror located at an angle of 45 degrees. to the axis of the channel, mounted on a special frame and connected to the illuminator. The frame moves inside the channel on a special rod and can rotate around the axis of the channel. Telescopic the part is mounted separately and placed outside the forging under study; it does not serve to transmit an image, as in an ordinary P., but for a better view of the field of view captured by the P.. Lit.:
W e 1 d e g t F.f Entwicklung u. Konstruktion der Unterseeboots-Sebrohre, Jahrbuch der schiffbautechnlschen Gesellschaft, Berlin, 1914, 15,
p. 174; A Dictionary of Applied Physics, London, 1923, v. 4, p. 350; K 0 n i g A., Die Fernrohre und Entfernungsraeaser, Berlin, 1923. P. Tischbein.
“A genius thinks and creates. An ordinary man carries it out. A fool takes advantage and does not thank” Kozma Prutkov.
PERISCOPE? WHAT IS PERISCOPE? In the 19th century in Paris, on the embankment near the Louvre, passers-by were shown magic mirrors, with the help of which one could see unhindered through thick stone walls. This device consisted of a telescope, split in the middle (where a thick stone was placed) and containing four flat mirrors at an angle of 45. This was the first time that a new optical device, the periscope, was advertised.
MIRRORS. PERISCOPE IS BASED ON MIRRORS. Among all the everyday objects, there is hardly a thing more controversial and mysterious than a mirror. The history of the mirror began already in the third millennium BC. The earliest metal mirrors were almost always round shape, and their reverse side was covered with patterns. Bronze and silver were used to make them. The first glass mirrors were created by the Romans in the 1st century AD: a glass plate was connected to a lead or tin lining, so the image was more vivid than on metal.
THE RIDDLE OF THE MIRROR Glass mirrors reappeared only in the 13th century. But they were concave. The manufacturing technology of that time did not know a way to glue a tin backing to a flat piece of glass. Only three centuries later did the masters of Venice figure out how to cover a flat surface with tin. Gold and bronze were added to the reflective compositions, so all objects in the mirror looked more beautiful than in reality. The cost of one Venetian mirror was equal to the cost of a small sea vessel. In 1500 in France, an ordinary flat mirror measuring 120 by 80 centimeters cost two and a half times more than a Raphael painting.
THE MAGIC OF MIRRORS Since the 16th century, mirrors have once again regained their fame as the most mysterious and most magic items, of all ever created by man. Sober-minded people found mirrors more useful application. For two hundred years in a row, the intelligence services of Spain and France successfully used a cipher system invented back in the 15th century by Leonardo da Vinci. Main feature cryptograms were turned inside out. Dispatches were written and encrypted in a mirror image and were simply unreadable without a mirror. The same ancient invention was the periscope. The ability to observe enemies undetected using a system of mutually reflecting mirrors saved many lives of Islamic warriors. The children's game of sunbeams was almost universally used by all combatants during the famous Thirty Years' War. It's difficult to aim when thousands of mirrors are blinding your eyes.
CONSTRUCTION OF THE SIMPLE PERISCOPE Periscope (from the Greek peri “around” and the Greek scopo “I look”) is an optical device for observation from a shelter. The simplest form of periscope is a pipe, at both ends of which mirrors are attached, inclined relative to the pipe axis by 45° to change the path of light rays. In more complex options Prisms are used instead of mirrors to deflect rays, and the image received by the observer is magnified using a lens system. opticalmirrorslens prisms
P PERISCOPIC REMOTE A periscope (“look around”) is an elongated optical system for observation, enclosed in a long tube, at the ends of which mirrors are located at an angle of 45°, refracting the light beam twice at a right angle and displacing it. The amount of displacement (periscope offset) is determined by the distance between the mirrors.
Periscopes allow for all-round observation of the terrain when minimum sizes inspection holes. Depending on the purpose, the reach (height) of the periscope can be different, reaching, for example, in a special mast-mounted periscope for observation in the forest up to tens of meters. Trench periscope (ours) Trench periscope (Germans)
P ERISCOPE OF A SUBMARINE A periscope is a mandatory instrument for any submarine. The emergence of new technical means Surveillance on submarines by radar and hydroacoustics has not replaced the periscope. These tools complemented it, especially in poor visibility conditions (fog, rain, snow, etc.). Using a periscope, the submarine commander determines the direction (bearing) from the submarine to the target, the heading angle of the enemy ship, the distance to the target, its speed, and the moment of the torpedo salvo. American officer at the periscope
P ERISCOPE OF A SUBMARINE A submarine at periscope depth To prevent the enemy from noticing the periscope, the dimensions of its head protruding from under the water should be minimal. But for successful observation of air targets, the periscope head is forced to be made thicker so that the necessary anti-aircraft surveillance optics can be placed in it. Therefore, two periscopes are currently installed on a submarine: an attack periscope (commander’s) and an anti-aircraft periscope. The attack periscope is used to detect the enemy and monitor him during a torpedo attack during daylight hours with good visibility.
P ERISCOPE IS A MANDATORY DEVICE FOR ARMOR TURRETS, LOCKHOUSES, AND TANKS. Periscopes are also installed on modern tank vehicles. In military periscopes, prisms, rather than mirrors, are often used, which are also capable of changing the path of light rays, and in addition, the image received by the observer is magnified using a lens system.
P PERISCOPE MIRRORS SYSTEM FOR RIGHT-HAND DRIVE CARS Viewing angle of the road before and after installation of the Periscope mirror system The right photo shows a typical situation: a “Van” is driving ahead, but you cannot see what is in the oncoming lane. However, in the photo on the left, in the mirror of the periscope mirror system, it is clearly visible that there is a “nine” in front of the “Van”, and a car is driving in the oncoming lane. And in order to see this, you don’t need to constantly “jump out” into the oncoming lane, turning too far to the left. One glance towards the mirror of this periscope system is enough.
AND PREPARATION OF A PERISCOPE We all love the wonderful cartoon “Chip and Dale to the Rescue.” Remember - from what available materials did Gadget make the submarine and periscope? You can easily make a periscope yourself. To do this, you only need two mirrors and a narrow cardboard tube of sufficient length. The simplest is a vertical periscope, consisting of a vertical telescope and 2 mirrors installed at an angle of 45° to the axis of the tube and forming an optical system that refracts light rays coming from the observed object and directs them into the eye of the observer.
