XV EJERCICIO ECONOMICO
NOTA 2 - NOTAS AL ESTADO DE SITUACION PATRIMONIAL
Scientific Discoveries of the Gaslight Era 1800 – Alessandro Volta invents the electric pile,
an early battery.
1800 – Sir William Herschel discovers infrared light.
1801 – Giuseppe Piazzi discovers Ceres, the first known asteroid. By the end of the century, several hundred are known.
1801 – Johann Ritter discovers ultraviolet light by its action on silver chloride solutions.
1801 – Thomas Young splits a beam of light and recombines it, producing interference patterns, demonstrating that light behaves like a wave. 1814 – Jons Berzelius develops the 1- or 2-letter symbols for chemical elements still used today. 1820 – The continent of Antarctica is discovered. ca. 1830s-1850s – The First and Second Laws of Thermodynamics are proposed and refined, describing heat and work in a closed system, and introducing the concept of entropy.
1832 – Michael Faraday and Joseph Henry independently invent the electromagnet, demonstrating the connection between electricity and magnetism.
1846 – Michael Faraday goes public with his speculations that light is a form of vibration in magnetic lines of force.
1850 – The Law of Conservation of Energy is proposed by several physicists.
1859 – Charles Darwin publishes The Origin of the Species; The Descent of Man follows in 1871. 1863 – Gregor Mendel, the “Father of Genetics” formulates his ‘Laws of Inheritance’. While unnoticed for almost 40 years, when combined with Darwinian evolution, it forms the basis of modern field of evolutionary biology.
1864 – James Clerk Maxwell publishes his theories on electromagnetism, which build on Faraday’s earlier work. They predict radio waves and a luminiferous ether – a medium for the transmission of electromagnetic waves.
1868 – The spectrum of an unknown chemical element is discovered in sunlight. Named Helium, it is not discovered on earth until 1881.
1868 – Dimitri Mendeleyev develops the Periodic Table of the Elements, one of the foundations of modern chemistry. It predicts the molecular weight and properties of a number of elements unknown at the time - the first of these, Gallium, is discovered in 1875, confirming his predictions.
1875 – Sir William Crookes begins experimenting with cathode rays in evacuated tubes.
1877 – Oxygen is first liquefied. Over the next 30 years, every known gas is liquefied.
1877 – Phobos and Deimos, the two moons of Mars, are discovered by Asaph Hall of the U.S. Naval Observatory.
1877 – Giovanni Schiaparelli observes dark lines on the surface of Mars, which he calls “Canali” (‘channels’). This is promptly mistranslated as ‘canals’, prompting speculation of an intelligent, technological civilization on Mars.
1887 – In an experiment designed to prove the existence of the luminiferous ether, Albert Michelson and Edward Morley end up doing the opposite, showing that the speed of light is independent of the motion of the observer.
1887 – Heinrich Hertz, while conducting experiments trying to prove the existence of radio waves, discovers that metals will emit electrons when struck by light of short wavelengths – the photoelectric effect.
1888 – Hertz discovers radio waves, confirming Maxwell’s predictions from 24 years before. 1895 – Wilhelm Roentgen discovers X-Rays using a modified Crooke’s Tube.
1896 – Henri Becquerel notices that uranium ore could fog a photographic plate through a light- proof envelope, discovering gamma rays.
1898 – J.J. Thompson accurately measures the photoelectric effect.
1899 – Ernest Rutherford discovers the alpha particle.
1900 – Henri Becquerel discovers beta particles, and shows that they are identical to electrons. 1900 – Max Planck publishes the radical idea that energy comes in discrete amounts, which he called quanta.
1904 – Hendrik Antoon Lorentz, attempting to resolve the contradictory results of the Michelson/Morley experiment, proposes a series of equations describing how objects contract in length and time slows as velocity approaches the speed of light. These equations form the basis of Special Relativity.
1905 – In a series of papers, Albert Einstein proposes the Theory of Special Relativity, the Photoelectric Effect, in which a quanta of light, called a photon, behaves like a particle.
While the sciences underwent dramatic development during the 19th century, much of this change was evolutionary, rather than revolutionary – the gradual refinement of existing areas of knowledge, driven partly by the improvements in manufacturing technology that gave researchers more and more accurate instruments. This chapter lists some of the many scientific tools available to investigators.
Item and Description
Weight US Price UK PriceAnalytical Balance, with weighing cabinet and weights 24.60 £ 5/1/6
100 gram capacity, resolution to 0.2 mg. The glass-sided cabinet stops air currents from disturbing the pans.
Barograph, with drum chart recorder 24.25 £5/0/0
Recording barometer – chart drive is spring wound with an 8-day movement. Charts cover 24 hours. Unit is housed in an attractive oak and glass case, with drawer for charts and pens.
Barometer, standard 86.55 £ 17/17/0
” bore, high accuracy, with vernier scale. With kew (calibration) certificate.
Butterfly Net, Folding 4/3
Cadaver, suitable for dissecting 10.20 2 gns
As purchased from the “resurrection men”. Demand for specimens always outstripped supply, and in many places it was illegal to perform dissections – Massachusetts did not legalize it until 1830, and Georgia until 1887.
Calorimeter, Mahler-Coole Bomb Calorimeter 169.75 £35/0/0
Used to determine the specific heat content of a carbon compound of food. A precisely weighed sample is burned with compressed oxygen in a sealed “bomb,” and the resulting heat is measured. Requires an analytical balance.
Chemical Apparatus (glassware), for students 6.90 - 24.25 28/6 - 100/0
Chemical Balance, for students, with weights 13.80 57/0
Compass, Dip Needle, w/ Morocco leather case 9.75 £ 2/0/0
Used for mineral prospecting, it detects the angle of the earth’s magnetic field to the ground.
Compressor, High Pressure Gas Compressor 412.25 £85/0/0
Requires 1 horsepower; can supply 20-50 cubic feet per minute at 200 atm (2940 psi).
Crooke’s Tube, center cathode 2.18 9/0
Dip Needle, 6” 24.25 £5/0/0
Includes heavy iron tripod base, leveling screws and two spirit levels. Used to precisely determine the direction of magnetic fields.
Dissecting Gloves, finest Indiarubber, 1 pair 0.60 2/6
Dissection Kit, w/ pocket case, top quality 3.00 12/6
Contains 2 scalpels, 2 pair scissors, 1 pair forceps, egg blowpipe, file, combined skinning hook and brain scoop.
Drafting Tools, deluxe set 5.50 22/8
Electroscope, Gold Leaf 15.25 £3/3/0
For accurate measurement in radio-activity experiments, as designed by Professor Rutherford.
Furnace, Electric Arc Furnace 99.45 £20/10/0
For producing extremely high temperatures, for example when vaporizing metals. This model has colored mica shutters for observing the reactions. Uses currents of up to 250 amps.
Extra Carbon Electrodes, 800 x 40 mm, per pair 1.20 5/0
Geologist’s Set, with belt case 1.58 6/6
Geologist’s hammer/pick and chisel in a leather belt case.
Goniometer, with microscope 45.85 £9/9/0
For determining the angles and structure of crystals. Vernier reads to 2 minutes of arc.
Hydraulic Pump, High Pressure 281.30 £58/0/0
Can produce pressures up to 3000 atm (44,100 psi).
Killing Jar, Glass 1.65 6/9
For collecting insects – uses either chloroform or cyanide vapor.
Micromanometer 6.00 £1/5/0
Measures minute pressure changes.
Microscope, 70x - 295x, with case 11 lbs 45.00 £9/6/0
Microscope, Universal, w/ Zeiss Lenses, w/ understage illuminator and case 39.30 £8/2/0
Oil Immersion Lens 24.25 £5/0/0
Allows greater resolution, clarity, and brightness at high magnifications.
Polariscope attachment 6.00 £1/5/0
Permits samples to be viewed through polarized light, highlighting crystalline structure and stress patterns.
Mounting Kit 13.33 £2/15/0
All necessary equipment (slices, covers, media, microtome, stains, etc.), stored in an attractive mahogany cabinet.
Stains, 1 bottle 0.18 0/9
Synthetic dyes used to highlight structures within a sample.
Triple revolving nosepiece 4.15 17/0
Mortar and Pestle, 6“ 0.42 1/9
Planimeter 11.65 48/0
A sophisticated tool that measures the area of a region traced out on a map with the attached pointer.
Pressure/Vacuum gage, 3” (numerous ranges available) 2.15 9/0
Refractometer, Abbe 82.50 £17/10/0
Item and Description
Weight US Price UK PriceSample Case 0.97 4/0
Japanned tin box fitted with 26 glass sample tubes.
Selenium Cell, mounted on stand 14.00 £2/18/0
Cell changes resistance in response to wavelength/intensity if light. Very sensitive; mounted in an ebonite frame on an iron tripod – height can be adjusted.
Slide Rules and Calculating Instruments:
Boucher Calculator 8.50 35/1
2” circular slide rule in the form of a pocket watch.
Duplex Slide Rule, 10” 8.00 33/0
A more versatile slide rule, capable of everything the Mannheim Rule, plus trigonometric functions. The rule has scales on both sides, and when performing calculations, the operator will frequently move from one side to the other.
Mannheim Slide Rule, 10” 4.50 18/6
The basic slide rule – capable of multiplying, dividing, ratios, squares, cubes, and roots.
Thacher’s Calculating instrument, w/ 3” magnifier 45.00 £9/6s
Not Available Before 1882. In effect a 30 foot long slide rule divided into 20 segments and arranged as a cylinder. Capable of extremely accurate calculations out to four significant digits.
Specific Gravity Bottle, 100ml 0.30 1/3
A bottle with a precise internal capacity – used to determine the density of liquid samples.
Still, 1 gallon 8.75 36/0
For distilling purified water. All metal parts are tin-lined.
Spectrometer, Constant Deviation 121.25 £25/0/0
Table-top model with heavy iron base; has a vernier drum that reads directly in wavelengths. Used to determine chemical composition by the light emitted/absorbed.
Camera 31.50 £6/10/0
Designed to mount to spectrometer – 21-inch focal length lens.
Surveying Equipment:
Clinometer, Military 5.05 £1/11/0
Accurately determines slopes and grades.
Plane Table, 17” x 14”, w/ tripod 13.85 £2/17/0
Used as the drawing surface for making maps. Includes a compass and sight rule, and metal tripod.
Surveying Chain, iron 1.95 8/0
Surveying Rods, 5’, pair 0.85 3/6
Theodolite, 5” scope, w/ tripod 121.25 £25/0/0
Telescope, Astronomical, 2” Refractor 43.15 £8/18s
Brass body, rank-and-pinion focusing. Alt-azimuth mounting of brass claw table stand.
Telescope, Astronomical, 5” Refractor 266.75 £55/0s
High quality instrument with 5 eyepieces, finder, and dew cap. Packed in a pine case.
Equatorial Mount, for 5” telescope 242.50 £50/0s
Iron column base, equatorial mounting with fine adjustment knobs and setting circles. Declination graduated to 1 minute of arc, hour to 15 seconds of arc. Base includes leveling screws and two spirit levels.
Clock Drive for Equatorial Mount 109.15 £22/10s
Sun Diagonal Eyepiece 5.11 £1/1s
Reduces light levels, allowing direct observation of the sun.
Tesla Apparatus 31.55 £6/10s
Thermograph, with drum chart recorder 23.65 £4/17/6
Recording thermometer – chart drive is spring wound with an 8-day movement. Charts cover 24 hours. Thermometer reads from 0 – 100 F.
Vacuum Pump, 3-cylinder, with stage and bell jar 87.30 £ 18/0/0
A sophisticated tool that measures the area of a region traced out on a map with the attached pointer.
Wavemeter, 0-5000 meter 140.00 £ 28/17/4
Not Available Before 1904. Determines the wavelength of an electronic signal (for example, a radio transmission.) The device uses a long spool of low-resistance wire, and detects the point of resonance.