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
Dietzgen Master-Pro Drafting Instrument Set
Drafting; Engineering; Architecture; Cartography
<p><strong>Physical Description: </strong>The drafting set is stored in a simple grey case with a red felt interior. The case only has three words on the outside cover: “Made in Germany”. The only markings on the inside of the case are the letters “DS” written in marker on the felt; presumably the initials of the original owner. Though the case is plain and simple, the drafting tools contained inside are intricate and precise. The set includes a large and small compass, a beam compass (with an extension), attachments for the compasses, both a ruling and technical pen, a pair of dividers, and a screwdriver. With these tools come replacement parts carried in capsules. The replacement parts consist of screws and heads for the compasses and ruling pen.</p>
<p><strong>Functional Description: </strong>The purpose of drafting tools is to create precise diagrams which convey how something functions or should be constructed. Drafting plays an important role in manufacturing, engineering, architecture, and cartography.</p>
<p>The function of the case is simply to store and protect the drafting tools, and keep them neat and organized. The interior of the case has slots fitted to the tools so that there is minimal movement when the case is carried. The dividers are used to quickly compare and transfer measurements, and to divide lines into segments. The compasses are used for drawing circles and arcs, and come in a variety of sizes to allow the drawing of very small circles in the case of the small compass, and very large circles in the case of the beam compass. The technical pen is used in order to draw lines of a fixed width, where as the ruling pen allows for the width of lines to be varied. There are a number of attachments that can used with the ruling pen and compasses in order to change between writing in ink and lead. Typically the initial revisions of a draft are done with lead, and then the pens are used later to create the final draft.</p>
Andrew Brusso, Rachel Fernstrum, Jacob Hedman, Nathan Regan, Zac Taylor
c. 1930
English
physical object
Germany
4242 compensating polar planimeter
Engineering; Mathematics
<strong>Physical Description</strong>: The Keuffel and Esser polar planimeter is composed of two individual pieces. One being the main body, and the other a tracer arm. Both sections are comprised of tarnished silver square rods with black markings indicating distance in millimeter; these rods being made of some black painted metal. Two dials are attached to the main body or larger section; one is horizontal, the other vertical. These dials are made of black painted metal with white lines and white numbers. The tracer arm is composed of a long square sections with a large balled pin on one end, and a large cylindrical mass on the other end that has a small pin on the bottom. The main body has a long square rod made of tarnished silver, with a black painted metal portion attached. This metal portion holds the aforementioned two dials. On the end of the silver square rod is a spike, this being attached to the rod via a black metal tab. The tracer arm and main body are combined by inserting the large balled pin into a hole on the surface of the main body. The object's case is a black rectangular box with a metallic clip latch. The inside of the case is lined with pear green felt material. On the inside of the lid is a white paper card with black old-style lettering. Inside the case and screwed to the bottom is a bronze stamped nameplate. <br /><br /><strong>Functional Description</strong>: The planimeter was used to measure the area of a 2d surface. It did this by having a tracer arm that remained stationary about a point, while the main body rotated and translated with the area’s curve. The dials attached measured the rotation and translation, and the resulting values could be used to calculate the area of the section enclosed by the device.
Cooper Sheldon, John Wyrzykowski, Ben Weigand, Nick Silvestri
1901-1936
physical object
English
Mechanical Engineering-Engineering Mechanics Building, 3rd Floor, Second Case from the Left
Weston D.C. Voltmeter, Model 45
Electrical Measurement
Front face with lid opened:
Knobs: Toward the top of the box on the front face, there are 3 screw knobs (two on the left, one on the right). Each dial has a knurled surface, and when unscrewed, reveals a metal electrical lead. Above the knobs on the left are circular labels with white text that say “300” and “150”. On the right, a similarly formatted inscription above the right knob has a “+”.
Front face surface: the entire surface is a black, knurly surface. On it is a circular boss that drops below the hinge mounts, such that the user can only see half of the circle. In the boss, there is a quarter-circular slot with glass in it such that the user can see the white label underneath it. A singular needle points to labels marked from 0 to 300, with increments of 20. Below those markings, there are similar markings in red instead of black, that increment by 10 and go from 0 to 150. Below that is the label “WESTON D.C. VOLTMETER”. The individual line increments on the white portion have 10 increments in between each labeled increment, with a longer split marking 5 increments.
Functional Description: This object is intended to measure voltage through use of the leads underneath the screw knobs. One attaches their charged leads to either the 300 or 150 lead and the “+” lead. When this is done, the needle points to the amount of voltage between the user’s charged leads.
The holes on the inside of the lid are probably for storing the electrical lead screw knobs, such that they do not get lost.
The instrument can be used on its back or on its bottom, and the user can use the latch to close the device during storage. When the leather strap was still there, it could be used to carry the device around.
The “correction” knob on the front can be used for fine-tuning/calibrating the instrument’s measurements.
The measurement of voltage can suit many applications, but in this case, it looks like it was for a specific class (The “EE” course prefix probably signifies the electrical engineering department).
Cooper Sheldon, John Wyrzykowski, Ben Weigand, Nick Silvestri
March 1930
English
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
American Thompson Steam Gauge
Steam Engines; Pressure Systems; Artillery
Physical Description:<br /><p dir="ltr"><span>The Thompson Improved Steam Indicator comes in a dark stained wooden box 285mm wide, 207mm deep, and 240mm tall. It opens about halfway up its height to reveal a number of objects. The box, as well as various components, are serial numbered 4994. Inside the box there are pockets as well as mounts for the various objects to go into which can be seen in the images provided.</span></p>
<p dir="ltr"><span>In the center is the steam indicator, which resembles two off-center attached cylinders screwed onto a mount. The cylinders are both 90mm in height and 50mm in diameter. The top cylinder has a slot to affix a cardstock, a stylus arm and pull string. The bottom cylinder has the arm holding the stylus and a spring inside to control the stylus arm. The bottom of the bottom cylinder has threads and ties to the mount on the bottom of the box, as well as thumb bars on the bottom to attach or unattach it by hand.</span></p>
<p dir="ltr"><span>The steam indicator comes with 6 springs numbered 10, 20, 30, 40, 60, and 80, which range in length from 53-63mm long. These springs are threaded onto mounts on the upper half of the box and can replace the spring inside the bottom cylinder of the steam indicator. This allows the system to make more precise graphs depending on the pressure that the engine is putting out.</span></p>
<p dir="ltr"><span>In addition to the above, there are also two globe shut-off valves with thread sizes of 20 and 25mm. The valves come with caps for one side to prevent damage to the threads that could result in inadequate attachment . There is also a torque wrench used to tighten the lower cylinder onto the engine that the indicator will be attached to. There is also a small vial of oil, for the joints of the stylus arm or the springs. There was also a specialized wrench designed to tighten the components in order to prevent gas leaks. The final component was a ruler with a screw driver end that allowed for the dismantling of the indicator as well as measuring the height of the graphs drawn by the arm allowing the user to find the pressure in the system.</span></p>
<p dir="ltr"><span>Functional Description:<br /></span></p>
<p dir="ltr"><span>In order to use the Thompson steam indicator, the user fastened</span><span> the stainless-steel ball valve to the steam engine being analyzed. The indicator was then be fastened to the open end of the ball valve via a threaded connection. With the ball valve opened, the steam within the engine’s piston</span><span> exerts pressure on a spring enclosed within a 100 mm tall, 30 mm diam. cylinder of the indicator. A plunger connected to the spring is </span><span> </span><span>forced upward depending upon the force received by the spring. The motion of the plunger moves the 80 mm long arm vertically, which determines the markings made by the attached pencil. The pencil marks a piece of paper, which is wrapped around the upper cylinder (90 mm tall and 51 mm dia) of the indicator. Wrapped around this upper cylinder is a string whose function is to rotate the cylinder about its center. If the string were left free to hang, the steam pressure pushes the pencil upward, making a straight vertical line on the paper. However, the string was fastened to a component of the engine to allow for the engine piston and the cylinder to move in unison. The string moves the cylinder of the steam indicator in unison with the piston throughout the entire stroke, and a continuous marking is made to illustrate the pressure at each point of the stroke as the pencil is moved upward and downward while the cylinder pivots throughout the process. Thus, the vertical motion of the pencil graphs changes in pressure, while the rotation of the cylinder indicates the phase of the piston cycle, and so in unison the pencil plots a diagram of the pressure cycle in the engine.</span></p>
<p dir="ltr"><span>The indicator was designed to record the stroke of a steam engine, particularly locomotives. At the start of the stroke, the inlet valve opens completely, allowing the maximum force to be applied to the spring by the steam. The pencil marks a horizontal line at its highest point in the cycle from left to right. At cut-off, the inlet valve closes and expansion of the steam occurs, during which the force gradually decreases. This phase is indicated by a pencil mark resembling an exponential decay curve. At release</span><span>, the exhaust valve opens, releasing the steam and the force is at its minimum, resulting in a straight horizontal pencil mark at the lowest point of the curve—this time from right to left. When the exhaust valve closes, compression occurs, causing a gradual rise in pressure. When the inlet valve opens again, the gradual increase in pressure becomes a sharp increase, causing the pencil to mark a straight vertical line returning to the first point of the cycle when the steam pressure exerts its greatest force on the spring. The end product of this device is a card illustrating the change in pressure throughout the continuous cycle of the steam engine. For an engine operating at 250 RPM, the device could generate one cycle plot (or card) per minute.</span></p>
<p dir="ltr"><span>The spring within the indicator can be replaced with a larger spring to record higher steam engine pressures. The set of springs are marked according to their compressive strength: the spring marked #100 converts the force from 100 psi gauge-pressure</span><span>steam into a pencil movement of one inch, a #80 spring converts 80 psig steam into a movement of one inch, and so on.</span></p>
<p dir="ltr"><span>Though the steam indicator was primarily used on locomotives, it could also be applied to traction engines and artillery</span><span>. Due to the high cost of the indicator, it was seldom used on traction engines beyond the confines of the factory in which it was produced. When applied to heavy artillery, the oil in the recoil chamber would replace the steam as the working fluid and exert a pressure on the spring.</span><span> The string would be fastened to the barrel to allow for the recoil movement to pull on the string.</span></p>
Elsa Schwartz, Collin Graf, Sarah Hartman, Joel VanLanen, and Patrick Demorest.
1904
English
Physical object
Serial no. 4994
United States of America
Raman Spectrometer
Chemistry, Spectroscopy
Functional: The Raman Spectrometer was and is used to measure stretching of bonds by measuring the inelastic scattering of light, which are output in lines of light also known as excitation lines, for the sample being collected. To test a sample the experimenter would place a glass capillary tube with a sample of the material being detected on the sampling apparatus, which is a black pedestal surrounded by concave mirrors, or under the microscope. The mirrors found around the apparatus will reflect light back at the sample from different angles so as to get the best reading of raman by testing the sample from all angles. Another way to test the sample would be to place the sample under the microscope, which is found to the left of the black pedestal when viewed from the front, on a glass plate. The microscope then scans the energy lines using its own scanning mirrors to measure the sample from all sides. The microscope is best utilized when something is under high temperatures and pressures (Hariba). Next the laser must be set to the right intensity and frequency, which can be determined by the ampere meter and the power meter, depending on the sample. “Samples are excited using either an argon ion laser or krypton ion laser which provide a multitude of excitation lines”(University of Sydney). This allows for accurate measurement of the vibrations of the sample. The laser is initiated by the user and once turned on will shine through a series of mirrors ,located around the base of the machine, and lenses, which are maneuverable and set by the operator to concentrate the light to one intensity before it hits the sample, which can also be moved up and down using the black knob attached to the apparatus. The concave mirrors will reflect the laser back towards the sample and then the shift in wavelength is then observed for the sample by a detector, in this case a photomultiplier, that measures the intensity of light leaving the sample. The photomultiplier provides analysis of the sample around the range of 1.5 um. The machine will also output a numerical value for the change in Raman on the top of the machine. The experimenter then reads this information given a graphical representation of the shift in wavelength.
Physical: The Raman Spectrometer consists of a large rectangular center module made of sheet metal. Surrounding this main piece are various instruments and dials. The whole system is set up on a table; on the back side of the center structure there is a laser emitter which is the longest object on the table, extending the entire length (1820 mm). The laser is sent through a series of lenses and mirrors that wrap around to the front of the system and shine into the sampling apparatus. The sampling apparatus is a stage in a square box with concave mirrors located on three out of the four faces with the other face allowing the laser light in. To the right of the sampling apparatus is a microscope that is used similarly to the sample apparatus. On top of the main housing, from left to right, there is a power meter in the front, in the middle back there is a meter measuring cm and change in centimeters, and on the far right there is a small digital display. The on/off switch is located on the right face of the machine behind the microscope.
Emily Lilla, Patrick Kidwell, Jacob Walcott, Kennedy Oparka, and Kelsey Bland
1928: Invented
C.V Raman & K.S. Krishnan
Similar to IR Spectrophotometers
Physical Object
English
U 1000
Radiotron
<em>Physical Description</em>: The Radiotron is a tall glass tube that stands 41cm high. The total width of the Radiotron is 25cm. The main glass sphere has a diameter of 18.34 cm. Attached to one side of this sphere is a tubular piece that has an outside diameter of 3.175 cm and an inside diameter of 2.5cm. The tubular piece is extruded 6 cm out from the sphere. The main body has two steel pegs that are used as electrical contact points. At the bottom of the structure there is a steel collar where wires are fed into the Radiotron. The Radiotron has many important internal parts; comprised of steel, steel mesh, and aluminum as seen in the figure which shows a detailed drawing of the Radiotron. <br /><br /><em>Functional Description</em>: The Radiotron is a triode vacuum-tube, working through a process known as thermionic emission, in which a cathode tube is heated so that it throws off electrons in the surrounding space. Surrounding the cathode is a metal plate which, if positively charged, will attract the ejected electrons, establishing a current. The radiotron is a triode vacuum tube, in which a small metal metsh is placed between the cathode and the anode plate. This mesh, if connected to a negative voltage, can reduce or shut off the stream of electrons from the cathode to the anode. This setup allows for small changes in voltage through the mesh to correspond to large voltage changes in the anode acting as an electric amplifier. The Radiotron is then attached as part of a larger circuit, in the case of our object, likely as a power amplifier aboard a navy ship.
Emily Oppliger, Grayson Hooper, Anthony Miller, Colton Kettlehut, Cam Dulong
Related to vacuum tubes
Physical Object
English
Shimadzu UV160U Spectrophotometer
Physics
<h3>Physical Description</h3>
The spectrophotometer consists of four sections; a screen, a touchpad, a glass sample bay, a light bay, and a power control section. The spectrophotometer is similarly built to an early computer with the processing system as a base with a screen and touchpad on the top of the base. The processing system’s base is black metal before transitioning to a cream-colored metal. The power control section is the lowest control on the machine, near the base on the left side. There is an on/off switch in yellow, a fuse dial that is SA(100~117V) to 3A(220~240V), an AC power plug, and a small black dial. On the top of the base, to the left of the keypad, is a light bay. The light bay has a glass covering. Within the light bay, there is a light source, a focusing element, a sample bay, a second focusing element, a light dispersing element, and a CCD array. This is all visual while peering into the compartment. Over the light bay, in the top left corner, is a small printer that uses a receipt-like paper. In the middle of the base top is the keypad. Dividing the keypad into three sections, left, middle, and right, there are about 11 individual pads, not including the number pad. On the left starting at the top left the column is File, Mode, Auto Zero, Return, Yes and No, in the order read like a book. In the middle, there is the typical number pad found on the calculator and then enter pad. On the right going in the same order as the left, there is the Copy, Chart Feed, arrow to the left (-), arrow to the right, and the START/STOP pad. Above the keypads is a monitor screen. On the front right side of the processing unit, there is the manufacturing permanent label. a silver manufacturing plate in Japanese and English on the side to the right. At the back right corner of the processing unit is a large air vent.
<h3>Functional Description</h3>
The Shimadzu UV160U Spectrophotometer works by placing a sample into the testing bay before turning it on. Once the sample is placed, the machine may be turned on to run the sample. The light bulb will shine a light that will be directed through two monochromators, these are film that focuses the light into a single wavelength. The double-focused ray of light is redirected in two directions towards the sample cell side and the reference cell side. The beams of light are both directed to the detector, which is processed by the computer. The computer will then will display the model that is preset using the keypad below the screen. Once results are reviewed they can be printed onto the slip above the sample bay for filing.
<p>A more thorough explanation is available in the C101-E142 UV Talk Letter Vol. 16 [see PDF with images]</p>
Emma Wade, Steven Walton, and Robin Chosa
Shimadzu
1985
Japanese
Physical Object
UV-160U; Cat No. 204-04550-51, Serial No. A11429030004
Forestry, Botany, Chemistry, Physics, 20th century, 21st century, medical
Portable Galvanometer
Physics Demonstration
<strong>Physical Description<br /></strong>Object comes in a wooden box. Box has a hinged lid and can be locked. Lock is made of metal with two screws on the face holding it to the side of the box. A leather strap is attached to the side of the box by the lock. There is a parchment tag attached to the leather strap. The strap connects to the box on two opposing sides with each side using two metal screws with washers to hold an end of the strap to the box. There is a brass placard on top of the lid of the box. On one side of the bottom of the box there are two numbers printed. The bottom of the box has four feet. There is a detachable curved metal piece that has cardboard slotted into one side. The cardboard has numbers written on it with tick marks below certain numbers. The actual instrument consists of a hinged scope affixed to a metal base. A knob behind the scope rotates a mirror that is positioned below the scope. The scope has a metal circular piece attached to the top. Two metal screws with holes are mounted behind the hinge of the scope. A brass knob is attached to the metal base and contains a water bubble. A solid, locking white oak case with leather handle encloses a elctrical-telescopic instrument. <br /><br /><strong>Functional Description<br /></strong>The box serves to protect the scope along with holding the metal measuring card. The knob on the metal base serves as level. The knob on the back of the scope is presumed to rotate a hanging mirror inside the scope. The exact function of the scope is unknown since it appears that it requires power (electrical) to function properly. <br />The case is opened 180˚ and the whole unit is leveled using the bubble level (the brass bullseye) on the rear part of the apparatus. The curved scale is attached to the inside of open top to use as a target and the telescopic eyepiece is raised up from the box. Two binding posts at the front of the instrument must take electrical leads to provide (variable) voltage or current to the sample cell, which appears to be the central black cylinder. Somehow the electricity will cause light to be refracted differently and the split prism below the eyepiece can then be used to read a number from ±17 (units?) to be read.
Gary Spikberg, Andrew Merdzinski, Andrew Stanley, Nick Lesko with additions by Steven A. Walton
Collection of Historic Scientific instruments at Harvard: <a href="http://waywiser.fas.harvard.edu/objects/14242/portable-galvanometer-with-telescope?ctx=24a8fbe0-083a-41ea-a973-5b23ad2b5882&idx=52">portable galvanometer with telescope</a>
1910
physical object
English
Serial Number: 154126
Exterior of Box top: G3 | MCMT-8885
Exterior of Box bottom: 2900 41481