|
School Spano |
|
||
|
Function For applying on luminous objects, as gas or electric lamps. | |||
|
|||
|
Description The cylindrical diaphragm lets a set of light rays pass across an asymmetric arrow formed by holes pierced along the lateral surface. | |||
Menu
|
School Castelvì |
|
||
|
Function Source for optical experiments. | |||
|
|||
|
Description The lamp has a concave mirror in reflecting metal. | |||
|
School Spano |
|
||
|
Function Point source for optical experiments. | |||
|
|||
|
Description A concave mirror directs the light produced by a lamp into a funnel that ends with a little hole. The ensemble is in varnished metal. | |||
|
School Spano |
|
||
|
Function Source for optical experiments. | |||
|
|||
|
Description Some bits of coals are placed at right angle and are adjustable separately or simultaneously thanks to two coaxial buttons, placed at the end of the screw that controls the above coil. The coals can have a diameter from 5 to 18 mm; the lamp can work with a current from 3 to 20 amperes, in alternate or direct current. The isolation of the binding posts for the bits of coals is made with a mica strip. The removable sheet iron cover has a lateral window closed by a mica sheet, that can easily be blackened with smoke to observe the size of the arc. The body of the arc is hinged on a 14-millimetre tube, sliding in the support column. The lamp can be oriented in all directions. | |||
|
School Spano |
|
||
|
Function Apparatus used to follow the apparent path of the Sun. | |||
|
|||
|
Description The apparatus is used to deflect the rays of the Sun towards the inside of a laboratory of physics to have a source of light. The model is completely in brass, with a silver plate mirror and a black mirror. The control is made from the inside with a tangent screw for the rotation on the horizontal axis of all the apparatus and with a rack for the mirror. A diaphragm is enclosed with a rectangular variable slit. | |||
|
School Spano |
|
||
|
Function To measure the luminous intensity of a source. | |||
| |||
|
Description After the decision of the Congress of Geneva, the most commonly used standard source is that proposed by Siemens and studied by Hefner. In this we can burn the amyl acetate with a solid wick, that fills completely the tube of nickel silver which has an 8-millimetre internal diameter and is 3-mm thick. The height of the flame, measured 10 minutes after the lighting, must be 40 mm and it is controlled thanks to a finishing line formed by an obscura camera supplied with the lamp. In this case and when the flame burns in calm and pure air, the value of the source is 0.053 Violle unities. | |||
|
School Spano |
|
||
|
Function Apparatus for illustrating the rectilinear propagation of the light, for the shadows and for Rumford’s photometer. | |||
|
|||
|
Description The apparatus includes: a paper screen on a wooden frame with a foot that holds it vertically according to its height and length, a brass foot with a column with a set screw on which we can fix a darken metallic disk for shadows and half-lights; a cardboard disk with a central hole for the rectilinear propagation of the light and for the obscura camera, a darken metallic pole for Rumford’s photometer; a support for three candles placed at the vertexes of an equilateral triangle. For the rectilinear propagation and the obscura camera we use the candlestick, the cardboard disk and the screen. For the shadows and the half-lights we use the candlestick, the metallic disk and the screen. For Rumford’s photometer we use the metallic pole, the screen, a candle and a group of four candles. | |||
|
School Spano |
|
||
|
Function To measure the luminous intensity. | |||
|
|||
|
Description The Bunsen photometer is of a grease spot type, with a screen made of interchangeable paper that can be put upside down for two readings. There is also a mirror on both sides of the screen. One of the board guides is divided in cm with the zero in the centre. | |||
|
School Castelvì |
|
||
|
Function To study the reflection laws. | |||
|
|||
|
Description The apparatus is made in varnished metal. The index turns on the axe of the half-cylinder. The mirror, joined to the index, reflects the light that comes from a slit. | |||
|
School Castelvì |
|
||
|
Function To study the refraction laws. | |||
|
|||
|
Description A half-cylinder container in varnished metal. A slit for the light is placed on the plane wall. A scale to measure the refraction angle is placed inside the curved surface. | |||
Menu
|
School Pellegrini |
|
||
|
Function For experiments of geometrical optics. | |||
|
|||
|
Description A metallic disk with a degree division is placed on a strong and heavy tripod. Around the axis of the disk a half-cylinder is turning and can be fixed on a position. It is useful to darken partially the disk during the experiment. The half-cylinder has a window with 5 slits where the light rays pass. These accessories are supplied with the disk: a concave and a convex mirror, a half glass disk , a trapeze, a double-concave lens, a double-convex lens and a glass disk. These accessories must be placed in the centre of the optic disk, where they are fixed by a branch that compresses them on the disk. | |||
Menu
|
School University (1), Spano (2) |
|
||
|
Function To study the reflection, refraction and the total internal reflection. | |||
|
|||
|
Description A vertical circle of 37 cm diameter is divided, on the four quadrants, from 0 to 90 degrees, and it is supported by a tripod. Two independent alidades with an index turn on the axe of the circle. In the circle an index on the alidades gives the angle that they form with the vertical diameter. This is represented by a ruler that individualizes the perpendicular to the reflecting or refracting surface in the incidence point. On the horizontal diameter of the circle we can fix a flat mirror or a hollow half-cylindrical glass that can be fiiled with some liquid. With the mirror we can verify the reflection law; with the half-cylindrical glass we can verify the laws of refraction, and the total internal reflection. We can also determinate with good approximation the critical angle of the liquid, and the refraction index. | |||
|
School University |
|
||
|
Function To study the phenomenon of the refraction with special reference to crystallographic and mineralogical studies. | |||
|
|||
|
Description The instrument is placed in a container closed with a key. It has a micrometric device, a magnifying telescope (2 or 3 times ), a reducing telescope (to ½ or 1/3) (both with the regulation of the diaphragm) and an objective for microscopes for a direct observation of the crystal and the hemisphere. The latter, with 40 mm diameter, is made of flint glass. Its index of refraction is 1,8904 for the yellow light. We place the crystal on the surface of the hemisphere The light is reflected by the mirror, crosses through the hemisphere and is reflected by the plane surface of the crystal. Then it goes to the telescope which rotates on a horizontal axis; on this telescope we fix the critical angle of the total internal reflection in correspondence with the intersection of the grating. From the measured angle we can calculate the refraction index. | |||
|
School University |
| ||
|
Function Accessory of the crystal refractometer. | |||
| |||
|
Description It is formed of a circular vernier and of an eyepiece, supported by a metallic pole with a circular basis. There are two images. If you rotate the vernier, an image is at rest while the other image follows the rotation. | |||
|
School University |
|
||
|
Function To study the phenomenon of the refraction across liquid substances. | |||
|
|||
|
Description The apparatus is made of a cubical brass frame. The bottom is made of brass with four little feet. The lateral surfaces and the diagonal divider are made of glass. The ensemble appears as made of two rectangular prisms. | |||
