Geissler Tube
Physics
<h2>Physical Description</h2>
This Geissler tube is approximately 155 centimeters long and weighs 984.4 grams or about 2.17 pounds. The outer tube is made up of symmetric sections of long tubes with a large bulb at the center. These sections themselves contain smaller sections of various tubes and bulbs. These smaller sections hold the conducting fluids and rare gases that when electrified create different colors of light. These smaller sections of glass tubing were made to be attention grabbing with swirling, spiraling and zig-zagging shapes. <br /><p><br /><strong>Condition:</strong> Damaged, electrical damage that blackened one side and knocked the platinum electrodes loose. The instrument may possibly work with a tesla field. This Geissler tube is missing the small wires that should extend from both ends to allow it to be hooked up to a power source.</p>
<h2><br />Functional Use</h2>
A Geissler tube is a gas discharge tube that lights up or fluoresces when a current is applied to the electrodes at either end of the tube. Geissler tubes were a novelty used for entertainment, but could also be used for demonstrations in classes like physics or chemistry. They were also used as high voltage indicators because they light up without contact when brought near a high voltage alternating current. Unfortunately this Geissler tube has a broken electrode on one end and is inoperable. To use the Geissler tube, the user must apply high voltage across the electrodes on each end of the glass tube. When a current is applied and flows through the tube, an electrical field is created between the two electrodes. In general, any free electrons in an electrical field will accelerate from the negative electrode towards the positive electrode. The electrons in the tube accelerating from the negative electrode to the positive electrode, will collide with the gas molecules in the tube. This collision may cause the electrons to give some of their energy to the gas molecules they are colliding with causing the gas molecules jump to a higher energy or excited state. The gas molecules do not stay in their excited state, instead they get rid of their excess energy by emitting their excess energy as light. The energy that is emitted is equal to the difference in energy between the gas molecule’s normal state and excited state. This energy determines which color of light will be emitted. The energy of the light is inversely related to the wavelength of the light and the wavelength of the light emitted is associated with a certain color of light. For example, Mercury vapor (Hg) can emit purple, blue, green or yellow color lights depending on how big the energy gap is between its excited and normal state. If the energy gap, and therefore the energy emitted is very large, Mercury will emit a purple light which has a shorter wavelength. Conversely if the energy emitted is smaller, Mercury will emit a green or yellow light which both have longer wavelengths. Although they have used almost all kinds of gasses in experimentation, Noble gasses such as Argon and Neon were favored for Geissler tubes as they are easier gasses to excite and produced a greater spectra (glowing light). Different gases have specific colors of light they can emit and so the color that the Geissler tube lights up depends on the gas inside of it.
Elisha Earley, TJ Johnston, Nick Littlefield, John Medley, and Anna Polk
Procured around the 1960's. Purchased back when Michigan Tech was transitioning names from Michigan College of Mining and Technology (MCMT) to Michigan Technological University (MTU)
English
Physical Object
No accession number
United States
Crookes tube (X-ray generator)
Mineralogy; Physics; X-ray research
Physical Description: The body of the Crookes tube instrument consists of a copper cube, in the center of a metal stand. The stand consists of a long tube with three legs protruding from the base. There are two additional tubes that extend beyond the cube's surface. When looking at the instrument from the front, extending to the right is a glass cylinder that has copper tube extending the length of it on the inside. Less than halfway down the copper tube inside the glass cylinder is a metal ring that has holes along its circumference. Adjacent to the glass tube, pointing towards the viewer when looking at the instrument from the
front, is a metal tube. On the upper half of the instrument above the cube, there is a metal tube that narrows in diameter towards its top. The are several places that rubber vacuum tubes would attach to create a vacuum, two at the end of the glass cylinder, two at the end of the tube protruding from the top, and one directly attached to the main cube.
Functional Description: To operate the Crookes tube a voltage is applied between the metal electrodes at either end of the glass tube. The electric field produced by the application of a voltage causes the gas particles in the tube to accelerate and collide with other gas molecules. If the energy of the collision is high enough an electron will be forced off the gas molecule and a positive ion will form. This process of ionization will continue to occur as a chain reaction until most of the gas molecules in the tube have been ionized. The positive ions are then attracted to the negative cathode, and when the ions collide with the metal the electrons are removed from the surface. The voltage being applied to the tube causes the electrons to accelerate as they all move towards the positively charged anode at the other end of the tube. Due to the increased speed the electrons collide with the wall behind the anode which causes them to become excited. As the electrons become excited and return to their original energy level, x-rays are produced. The x-rays will then exit through the opening at the end of the metal tube which sits perpendicular to the glass tube. A sample can then be placed a certain distance away from the opening and when the x-rays hit the sample an image will be produced on a screen behind the sample.
Nicole Bliven, Shelby McGuire, Zach Nelson, Joseph Aldape, and Will Christian
c. 1940-1950
English
Physical object
United States of America
Earth Inductor
Physics; Electromagnetism
<h2>Physical Description</h2>
A rectangular, lengthwise symmetric, wood frame (163cm X 43.5cm) that houses two rings (inner diam. 23cm, outer diam. 30.5cm), one on each side of the line of symmetry, which acts as spindles for wire. The frame is held together with brass fittings and brass screws. A newer-looking aluminum crank centered on one long side of the frame is connected by a shaft to a set of seven numbered brass gears (diam. 8cm) along the opposite side of the frame. The gears rotate the spindles 360° while keeping them parallel. Each spindle, around which wire can be coiled over 100 times, has a commutator through which an electric current can be measured. <br /><h2>Functional Description</h2>
The instrument demonstrates Faraday’s Law of Induction, which states that a changing magnetic field (in direction or in magnitude) passing through a circuit generates an electromotive force, or voltage, in the circuit. The Earth Inductor instrument uses earth’s magnetic field, which is approximately constant in time but varies by location, to induce a current in a coil of wire. The operator turns the handle, rotating the wooden circle containing the coils of wire, which causes the amount of magnetic flux passing through the coil to change based on its angle with respect to earth’s magnetic field. An ammeter connected to the metal terminals records the generated electric field through time, and the angle of earth’s magnetic field lines can then be determined based on the angle of the coil at which the maximum electric field is measured. The large number of turns of wire in the coil, over 1000 turns, amplifies the resulting current because the observed electric field is proportional to the number of wire turns. Earth’s magnetic field is relatively weak, normally requiring very sensitive instruments to measure. Mutual inductance is a second phenomenon demonstrated by the earth inductor, and is the reason for having two connected coils. The current generated by a single coil from earth’s field is not constant with time, and therefore generates its own independent magnetic field. This secondary field influences the electric field of a secondary, distant coil, and the difference between the primary induction and the secondary induction can be measured.
Ajay Vasu, Zane Barker, Daniel Ratkos, Luke Weidner, Lindsey Wells
1920-1940
English
physical object
United States
Agate Mortar and Pestle (1/3)
Geology, Mineralogy and Crystallography
<strong>Physical Description</strong><br />There are three unique agate mortar and pestles at A.E. Seaman Mineral Museum. The largest mortar measures three centimeters in diameter at the base, while the matching pestle measures five centimeters in length. This mortar and pestle set is a light brown color with translucent areas. The pestle is lighter than the mortar. Both are cut from agate, which gives the set a marbled and inconsistent color pattern. The mortar is a rounded bowl on the inside, but the outside edges form an octagonal shape. Each end of the pestle is rounded; one end of the pestle is smaller in diameter than the other by four and one half centimeters. <br /><br /><strong>Functional Description</strong> <br />The mortar and pestle has been used in laboratories for centuries for grinding and crushing various substances. This mortar and pestle is still in use for grinding powders for X-Ray diffraction. The mortar is shaped like a bowl in order to hold a certain amount of the substance to be ground. The pestle is then used to mash and grind the substance in the bowl until the desired consistency is reached. The agate mortar and pestle is used in circumstances where cross contamination must be avoided. This is because agate is one of the finest, most non-porous natural materials available for a grinding surface. Bacteria, contaminants, and other particles cannot penetrate the material.
Savannah de Luca
unknown
n/a
Physical object
none
Microscope Slides in Box
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These microscope slides are contained in a lightly colored oak box, featuring thin cuts of wood and brass hardware. The locking mechanism on the front of the box is made up of two rotating hooks on each side, located near the top of the box, and two open loops, located near the bottom of the box. The top of the box reads, in hand-written black ink, “Other Common Rock Forming/Minerals.” The box opens up to reveal 282 glass microscope slides and 18 empty slots for missing slides. Each slide is made of a mineral sample pressed onto a cut of glass. Each slide has two labels attached to the glass; on one of the labels, a typed font displays the words: “MICHIGAN MINING SCHOOL. NO.” and features a number unique to each mineral sample. On the other label, a name, number, and location of each mineral sample is hand-written in black ink. <br /><h2>Functional Description</h2>
The glass slides contains a mineral to be examined at a microscopic level. Slides were used to press thin strips of minerals flat and hold them easily for examination. The slide containing the mineral was placed and secured, and then the microscope is adjusted for viewing.
Savannah de Luca
c. 1880
English
Physical object
DM 31417
Wooden Crystal Models - Tetragonal
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of light pearwood. Each model is precisely shaped with correct facets and angles to illustrate seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Each individual model is unique, the length varying from 3 to 7 centimeters and the width from 2 to 7 centimeters. Some have identification numbers carved into them, which pertain to their original kit number given by the manufacturer. Some have handwritten numbers in black ink on their flat faces, which identify the name of the crystal they represent.<br /><h2>Functional Description</h2>
These crystal models were made as a tool for teaching crystallography and the morphology of crystals. Each model has unique external symmetry that replicates the actual crystal, providing a hands-on teaching practice that is still used today in class rooms. This specific collection is still used to teach crystallography at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Triclinic/Trigonal unpaired
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent. <br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Monoclinic/Triclinic
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent.
<h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Twins
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent.<br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Hexagonal
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent. <br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none