Optical camera in walnut wood equipped with a "Triplet Cooke" lens of 15.2 cm of aperture and 107 cm of focal distance. Initially this camera was mounted on the Salmoiraghi equatorial as a collimator. In the early 1900s, with this instrument Cerulli discovered a new asteroid to which he gave the name ìInteramniaî, from the Latin name of Teramo, and found the comet 1910e. Subsequently, in 1955, the camera underwent some repairs and adaptations in order to obtain, with the installation of the second Cooke camera (with 8 cm aperture, 48 cm focal distance) on the equatorial both stable and balanced.

Initially this camera was mounted on the Salmoiraghi equatorial as a collimator. In the early 1900s, with this instrument Cerulli discovered a new asteroid to which he gave the name ìInteramniaî, from the Latin name of Teramo, and found the comet 1910e. Subsequently, in 1955, the camera underwent some repairs and adaptations in order to obtain, with the installation of the second Cooke camera (with 8 cm aperture, 48 cm focal distance) on the equatorial both stable and balanced.

Small photographic camera accompanying the large Cooke refractor, made of walnut wood and connecting flange for the refractor in gilded brass. It has guides on which the plate holder is inserted.

Small photographic camera for the Cooke refractor. This essentially consists of a camera with a curtain shutter on the focal plane with the possibility of adjusting both the speed of the curtains and the distance between them. By combining the two systems, exposure times ranging from 1/25 to 1/1000 of a second can be obtained. Together with the chamber there is a walnut sled with a gilded brass guide, where a plate holder of the same wood is inserted. This allows on the same photographic plate, sliding it on the guide, three different exposures.

The dry electromagnetic chronograph is an instrument used for recording on a paper strip the instant in which the passage of a celestial body under observation on the meridian took place. The instrument is mainly made up of two parts: a device for advancing the paper (at constant speed) and a writing tip system. The recording takes place through two arms, with points that pierce the paper, controlled by electromagnets: one connected to a clock (marks the seconds) and the other controlled by the observer marks the instant of the astronomical phenomenon. This tool was used in conjunction with the passing tool.

The dry electromagnetic chronograph is an instrument used for recording on a paper strip the instant in which the passage of a celestial body under observation on the meridian took place. The instrument essentially consists of two parts: a device for advancing the paper and a system with writing tips. Registration takes place via two arms, with points that pierce the paper, controlled by electromagnets: one connected to a clock (marks the seconds) and the other controlled by the observer using a telegraphic key (marks the instant of the astronomical phenomenon ).

The marine chronometer was used to determine longitude at sea. It is an innovative half-second chronometer with free escapement with compensated balance wheel; The innovation consists in incorporating temperature compensation into the balance wheel and introducing a detent into the escapement so that the balance wheel can move freely. The chronometer movement, blocked by a crown with glass, is contained in a gilded brass case which is fixed on a cardanic suspension to give stability and flatness to the instrument.

An airtight cylindrical chamber containing the two cells, one with rubidium (Rb) and the other with sodium (Na), which receive the light through a two prism positions; the two Lindemann electrometers (meters) are enclosed in the underlying rectangular chamber, which also acts as an electrostatic screen and as a support for the 2 microscopes. The operating principle is to transform the starlight into an electrical signal, thus allowing an objective and precise measurement of the luminosity of the stars and its variations.

First photometer built in Collurania, with a photoelectric cell, with a cardan-suspended electrometer. The instrument consists of a cylindrical chamber to be inserted into the ocular end of the Cooke refractor. The operating principle is to transform light into something measurable: this is achieved by exploiting a physical property of alkali metals that emit a number of electrons proportional to the energy of the incident light, thus allowing an objective and precise measurement of the luminosity of the stars. and its variations.

This instrument is used in astronomy for the indirect measurement of apparent stellar diameters by counting the interference fringes and measuring the corresponding wavelength. The instrument consists of two bronze sleeves. On the face of one of the two sleeves there are the slit-carrying slides while the other sleeve, which remains external to the eyepiece of the telescope, carries the position circle and the eyepiece. The instrument is also equipped with a printer position circle with numbers and strokes that can be printed on a strip of paper using an ink-soaked ribbon.

The vertical sundial in true solar time is made up of a marble slab (white Carrara) on which the reference marks and the hours are engraved. The Babylonian hour clock is located on the east facing wall of the central building of the Observatory. The clock indicates how many hours the Sun has risen (horae ab ortu Solis). This system of counting the hours has been in use throughout the Middle East until a few decades ago and its origin dates back to ancient times. A brass rod called an "orthostyle" is fixed perpendicularly to a certain point on the marble slab. The rod generates a line of shadow in the sunlight, the extreme point of which is the useful element for reading this watch. The extremity of the shadow of the orthostyle, running over the engraved lines, provides these indications: the hours elapsed since sunrise and the seasons.

The vertical sundial in true solar time is made up of a marble slab (white Carrara) on which the reference marks and the hours are engraved. The clock with "Italic" hours is located on the wall facing exactly south-west of the central building of the Observatory. The clock indicates how many hours have passed since sunset the previous evening (horae ab occasionu Solis). This system of counting the hours has spread throughout the Mediterranean basin since the 11th century AD, with the penetration of Arab culture in Europe. This system was the only one in use in Italy until almost the whole of the last century: hence the name "Italic". A brass rod called "orthostyle" is fixed perpendicularly to the marble slab. The rod generates a line of shadow in the light of the sun, the extreme point of which provides these indications: the hours elapsed since the sunset of the previous evening, the seasons, true solar noon and duration of the diurnal arc.

The micrometer works at the end of the Cooke equatorial telescope. It includes: a micrometric box, equipped with fixed wires and mobile wire, and a cylindrical sleeve inside which a tube runs, driven by the drum, at the two ends of which the Wollaston prism and a variable diaphragm are fixed. The sleeve within which the prism-holder tube moves is equipped with a junction whose bases can slide on each other in friction, so that the micrometric box and, therefore, the wire itself, can assume any orientation.

Grubb (Dublin) wire micrometer, works at the end of the large Cooke equatorial telescope. The gilded brass instrument has two parallel and equal micrometric screws, each of which carries a frame with wires. The lighting of the field and of the wires is given by an electric bulb embedded in a suitable cavity on the side of the frames. Originally the micrometer was equipped with positive eyepieces with amplification from 200 to 1500.

Small spring-loaded clock with pendulum oscillator beating half seconds, with brass escape wheel, anchor-type escapement with steel pawl. The dial, with a diameter of 10 cm in silver-plated brass, is divided into minutes shown on the outer margin, the hours in Roman numerals are shown inside, in an eccentric position, in the upper part, a small dial with a diameter of 3 cm shows the seconds scored ten by ten. The oscillation period of the pendulum can be adjusted by unscrewing or screwing a ring nut positioned on the rod which determines the displacement of the burnished metal lens along the suspension rod. The electrical contacts with which this pendulum is equipped were used to electrically synchronize other pendulums and record the whole seconds on the chronograph. The cabinet containing the instrument is made of walnut wood.

Weight clock with pendulum oscillator that beats sidereal time (time linked to the apparent diurnal motion of the stars), with anchor-type escapement at rest and brass wheel and hard stone vanes. Compensation with invar rod (steel-nickel alloy) which has a low expansion coefficient.

Weighted clock with pendulum oscillator beating the average time, with anchor-type escapement at rest, brass and steel wheel and electrical contacts to record the second on a chronograph and possibly to synchronize another clock. The compensation is mercury, contained in a glass container placed at the end of the pendulum rod, where the electrical contacts are also placed; these, with each swing of the rod, affect an electromagnetic system, placed on the internal wall of the cabinet, which, controlled by a regulating clock, allows the clock to synchronize.

Pendulum clock that strikes the sidereal second (time linked to the apparent diurnal motion of the stars), with suspension and compensation according to the system devised by Riefler, in which the anchor-type escapement is free, and the impulses are given to the pendulum by means of the suspension spring. The compensation is mercury, contained inside the pendulum rod, which with its thermal expansion compensates for the elongation of the suspension rod, despite the variations in temperature. This instrument is equipped with electrical contacts for recording the seconds on the dry chronograph.

Weighted clock with pendulum oscillator beating the average time, with anchor-type free escapement, brass wheel and electrical contacts per second. Compensation with invar rod (steel-nickel alloy) which has a low expansion coefficient.

Instrument for the direct observation of the electromagnetic radiation emitted in the visible by a determined celestial body. The spectroscope, which can be applied to the extreme eyepiece of the Cooke refractor, has a large format 5-prism dispersing system. The image of the star falls on a narrow slit, from here the light, made parallel by a collimator, first passes through a rectangle prism and then 4 prisms placed radially. The last prism, also a rectangle, inverts the optical path, returning the light to the 4 prisms, in order to increase the image of the spectrum; a lens converges light onto an eyepiece for viewing.

This instrument is used to determine the passage of a star on the meridian of the place and is able to move only in the direction of this plane. It is a small invertible that rests on a circular cast iron base, equipped with an altazimuth circle and two diametrically opposed magnifying cups. The instrument consists of a gilded brass telescope, whose objective measures 7.3 cm in aperture and 109 cm in focal length, which rotates around a horizontal axis supported by two vertical cast iron supports. The horizontal axis is made up of two opposite truncated cones, in gilded brass, connected in the center by a connecting cube on which the telescope is also fixed orthogonally to the axis. Particular attention was paid to fixing the prism inside the connection cube; this total reflection prism deflects the line of sight by 90∞ to complete the focal path on the impersonal Repsold micrometer, which is located at one end of the horizontal axis. At the other end of the horizontal axis there is installed the vertical circle, equipped with a movable arm, which carries three verniers and the relative magnifying cups (one of which is missing), a small spirit level and two small counterweights for balancing. .

Used to measure the zenith distances of the stars in any vertical plane. The instrument is supported by a zenith mount. The telescope has an aperture of 7.5cm and a focal length of 77.4cm. The instrument is equipped with a finely divided horizontal circle that can be read by two opposing micrometric microscopes. The vertical circle is equipped with a vernier, by which it is easy to estimate 10 ". Two Talcott latitude levels are fixed on the vertical but independent circle. In the lower part of the telescope there is a wire micrometer, with an eyepiece at 90∞ on the line of sight.

It is a refractor with an equatorial mount supported by a cast iron column, with 13.5 cm of aperture and 175 cm of focal distance. The telescope tube is made of walnut wood, while the objective holder and the eyepiece holders are made of brass. Defined as the "Comet Seeker" it was mainly used as a guide scope for the Cooke photographic camera (16.5 cm aperture), and in practice it proved not sufficiently robust to hold the complex stably. It is with this instrument that Cerulli discovered a new planet "Interamnia" and found the "Comet 1910 e". In 1955 the second Cooke photographic camera (8 cm aperture) was applied with the necessary modifications in order to obtain an ensemble with the necessary stability. Later, in the late 1960s, the "Cooke" cameras were replaced with a Zeiss astrograph (20 cm aperture 144 cm focal distance)