2 10 22 https://www.electrifying.collopy.net/files/original/4c37ab94b7236506e6fe014295bc5b14.png 70eae0335c5f0a4821fd26862c91045a Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Map Of Campus - 1926-1927 Handbook of the California Institute of Technology Description An account of the resource Every incoming Caltech undergraduate student receives the latest edition of the campus handbook, the little t. In the 2025–2026 edition, the little t has the “primary purpose of helping frosh get acquainted with the Institute” (Emily et.al “Preface”). However, the little t did not exist in its current form during Caltech’s earliest years. In 1926, it still bore its original name, Handbook of the California Institute of Technology. Even so, the handbook served a similar purpose. One section in particular has remained present from 1926 to 2026 for over a hundred years: the Caltech campus map and directory of buildings. Although the 2025–2026 little t provides only a link to a virtual interactive map, the 1926 handbook includes an engineering-style hand-drawn map, reproduced at the very front of the book. The building blocks are represented in little rectangular boxes, which does not represent the real shape of the infrastructures from an aerial view. They are more served as symbols that tell students where to go. Interestingly, the 1923 Caltech Catalogue has more detailed descriptions of the buildings on the map, but note that some buildings, such as Caltech’s Electrical System, are temporary (Catalogue 44). Bulletin of the California Institute of Technology Catalogue. Published by the Institute, vol. 32, no. 101, Dec. 1923. Handbook of the California Institute of Technology. Caltech. 1926-1927 Yu, Emily, Foster, Melissa, Yang, Benjamin. The little t 2025-2026. Published by ASCIT Creator An entity primarily responsible for making the resource The Institute Editors Date A point or period of time associated with an event in the lifecycle of the resource 1926-1927 Format The file format, physical medium, or dimensions of the resource Handbook/booklet Publisher An entity responsible for making the resource available Caltech https://www.electrifying.collopy.net/files/original/52e351be0b87a652876e557b8d14c736.jpg 0bb92bb2a5f2eff4a54916d28c8ccc5f Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Photograph Physical Dimensions The actual physical size of the original image 8" by 10" Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Construction of Florence Lake Dam in the summer of 1926 Creator An entity primarily responsible for making the resource Vic Stahl Source A related resource from which the described resource is derived The Huntington Digital Library https://hdl.huntington.org/digital/collection/p16003coll2/id/5690/ Format The file format, physical medium, or dimensions of the resource Photograph https://www.electrifying.collopy.net/files/original/2666ae867f78b93ac0faeabe08b8e9d7.jpg da106ca86603d2bee11e9e889c277e69 https://www.electrifying.collopy.net/files/original/ad2c2423daf0f0cafa1d8211fa86596c.jpg b97559b0218295db85aa8b61e3afbc78 https://www.electrifying.collopy.net/files/original/e0106baba736ab2bf8b055a49f65af1c.jpg 8893318d28a8dff0ee36dbdada66314c https://www.electrifying.collopy.net/files/original/19165f9709ec4a4f7b3d6f2cd0a9e242.jpg ad5d30e65429cc651bfa60ce53c6a22b https://www.electrifying.collopy.net/files/original/c6c3d5f094c65b25c3b15943557eac85.jpg 1075f5cc23f7e5126b366640efb076a0 Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Letter Physical Dimensions The actual physical size of the original image 8.5"x11" Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Letter From Westinghouse Electric to Royal W. Sorenson Description An account of the resource A decade after the Borel plant began operation, electricity requirements in Southern California had grown drastically. To meet the new demands, Henry Huntington commissioned engineer John S. Eastwood to design a new power plant to be built in the San Joaquin Valley, named Big Creek power plant (Hanson). Royal W. Sorenson, electrical engineer who worked at Caltech (then called Throop Institute) and inventor of the vacuum switch, was a consulting engineer for Huntington's Power Company (Caltech Office of Strategic Communications). This document is correspondence between Sorenson and Westinghouse Electric before the plant opened, who replied after Sorenson sent a report of "hunting" in the generators at Big Creek Station No. 2. Hunting occurs when the generator searches for the right frequency to operate at, causing power output fluctuations and damage to equipment. Westinghouse Electric instruct Sorenson in this letter to increase the voltage of the generators, as they suspect the issues were caused by underload. Big Creek powerhouse No. 2 opened in December 1914 (SCE), a decade after Borel. It marked one of the first major collaborations between Huntington and Caltech, which would eventually lead to the construction of the High Volts laboratory. <div class="csl-bib-body" style="line-height:2;margin-left:2em;text-indent:-2em;"> <div class="csl-entry">California’s Promethean Past by Victor Davis Hanson, City Journal Summer 2013. 26 Mar. 2014, <a href="https://web.archive.org/web/20140326171900/http://www.city-journal.org/2013/23_3_henry-huntington.html">https://web.archive.org/web/20140326171900/http://www.city-journal.org/2013/23_3_henry-huntington.html</a>.</div> <div class="csl-entry">Caltech. “Royal W. Sorenson Faculty Portrait.” Caltech Magazine, Caltech Office of Strategic Communications, <a href="https://calteches.library.caltech.edu/1250/1/Sorenson.pdf">https://calteches.library.caltech.edu/1250/1/Sorenson.pdf</a>. Accessed 15 Mar. 2026.</div> <div class="csl-entry">Catren, Robert Charles. A Thesis Presented to the Faculty of the Department of History University of Southern California.</div> <div class="csl-entry">Southern California Edision Company. “Initial Information Package for the Big Creek Hydroelectric System.” SCE, 2000, <a href="https://www.sce.com/sites/default/files/inline-files/2000_iip.pdf">https://www.sce.com/sites/default/files/inline-files/2000_iip.pdf</a>.</div> <div class="csl-entry">Westinghouse Electric & Manufacturing Company. 23 July 1914, California Institute of Technology Archives, Sorenson Papers Box 1.</div> </div> Creator An entity primarily responsible for making the resource Westinghouse Electric & Manufacturing Company Source A related resource from which the described resource is derived Caltech Archives, Sorenson Papers Box 1 Date A point or period of time associated with an event in the lifecycle of the resource July 23, 1914 Format The file format, physical medium, or dimensions of the resource Physical Letter Big Creek Huntington Sorenson https://www.electrifying.collopy.net/files/original/a8d332a2c7eb29278de96e8dc5c6a768.jpg d9d95286aabd760d25b424025a197114 https://www.electrifying.collopy.net/files/original/be9472504f31f620a5544f6522b346fe.jpg 03e7662875d9d921d866620f077a5241 Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Photograph Physical Dimensions The actual physical size of the original image 4" x 6 " Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Millikan-Sorensen Vacuum Switch Description An account of the resource Transmission of power is dangerous when high voltage drives immense amounts of current. When Big Creek finished construction, ultra-high voltage (up to 220 kV) was generated and ready to be transmitted [7]. Thus, significant safety challenges arose, specifically in regards to interrupting electrical arcs. The traditional oil circuit breakers that relied on oil to quench arcs faced growing problems such as fire risk, large size, and high maintenance [7]. Recognizing this, in 1923, Southern California Edison partnered with Caltech to build a high-voltage laboratory [4]. The photo above depicts all three switches that were developed and tested [8]. The bottom center shows the first prototype followed by the second on the left and the third prototype on the right. The large metal caps apart of the second and third switch were used to create vacuum-tight joints for the lead-in conductors [8]. The second vacuum switch was a larger version of the switch Sorensen and Mendenhall first tested [8]. From a 1926 paper by Sorensen and Mendenhall titled “Vacuum Switching Experiments at California Institute of Technology,” high success is reported as “the switch was operated as a single-pole switch to open and close this circuit more than 500 times without showing any burning of the switch contacts” [8]. It was even tested at the Torrence substation of the Southern California Edison Company where it was able to interrupt currents as high as 600 amperes at 12,780 volts [8]. Subsequently, the third switch was brought to Laguna-Bell substation where it was able to interrupt 926 amperes at 41,500 volts [8]! Works Cited [1] “100 Years Young: Big Creek Hydroelectric Plant Still Going Strong.” Edison International | Newsroom, https://newsroom.edison.com/stories/100-years-young:-big-creek-hydroelectric-plant-still-going-strong. Accessed 17 Mar. 2026. [2] “Power Lines Around Los Angeles: Isolation, Interconnection, and Aesthetics.” Boom California, 21 May 2020, https://boomcalifornia.org/2020/05/21/power-lines-around-los-angeles-isolation-interconnection-and-aesthetics/. [3] Fox, Donna, Robert J. McEliece, and Babak Hassibi. “An Electrifying Century: An Early History of the Caltech EE Department.” ENGenious, 8 Oct. 2010, engenious.caltech.edu/articles/history-EE-Department-century. Accessed 5 Feb. 2026. [4] Heilbron, J. L., and Robert W. Seidel. Lawrence and His Laboratory: A History of the Lawrence Berkeley Laboratory, University of California Press, 1990. UC Press E-Books Collection, https://publishing.cdlib.org/ucpressebooks/view?docId=ft5s200764&chunk.id=[section identifier]. Accessed 5 Feb. 2026. [5] Millikan, Robert A., and Royal W. Sorensen. Brief for Millikan and Sorensen. Robert A. Millikan and Royal W. Sorensen v. Talma T. Greenwood, Interference No. 56557, United States Patent Office, [Year, e.g., 1928], [Collection Name, e.g., Royal W. Sorensen Papers], [Box 3], Caltech Archives, Pasadena, CA. [6] Ornelas, Gabriela. “Big Creek’s Powerhouse 8 Marks 100 Years of Hydroelectric Power.” Energized by Edison, 8 Oct. 2021, energized.edison.com/stories/big-creeks-powerhouse-8-marks-100-years-of-hydroelectric-power. Accessed 5 Feb. 2026. [7] Record, Historic American Engineering. Big Creek Hydroelectric System, East & West Transmission Line, 241-Mile Transmission Corridor Extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA. Still image. California -- Tulare County -- Visalia, https://www.loc.gov/pictures/item/ca3976/. Accessed 17 Mar. 2026. [8] Sorensen, Royal W., and Hallan E. Mendenhall. “Vacuum Switching Experiments at California Institute of Technology.” Transactions of the American Institute of Electrical Engineers, XLV, Jan. 1926, pp. 1102–07. Semantic Scholar, https://doi.org/10.1109/T-AIEE.1926.5061306. Identifier An unambiguous reference to the resource within a given context https://digital.archives.caltech.edu/collections/Images/10.33-29/ Source A related resource from which the described resource is derived Caltech Archives and Special Collections, High Voltage Research Laboratory Date A point or period of time associated with an event in the lifecycle of the resource 1924-1926* https://www.electrifying.collopy.net/files/original/74875b67139ddcd5046be44dc25c5b2b.jpg f41cdbd31328391c9755b003407a7b6c Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Photograph Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Theodore von Karman trip to Hoover Dam Description An account of the resource This photograph captures Theodore von Kármán and Raymond Sanger (unknown involvement) during a 1933 visit to Hoover Dam while it was still under construction (1931–1936). Von Kármán's interest in hydraulics dates back to his early career. Following his graduation from the Royal Joseph Technical University in Budapest, von Kármán was appointed as an assistant in hydraulics, working there for three years. While at the University of Göttingen, he used a large hydraulic press for research on the strength of materials, bridging the gap between fluid dynamics and structural mechanics (Altenbach & Bruhns, 2020). The visit documented in this photograph coincided as Kármán was working to establish a hydraulic research focus at Caltech. Observations from visits such as this helped shape the goals and research direction of the hydraulics laboratory created at Caltech later that year. That laboratory would go on to work directly on similar hydroelectric infrastructure development projects using a perspective gained from Kármán's expertise in the aeronautical sciences (Heppenheimer 2007). WORKS CITED Altenbach, H., & Bruhns, O. T. (2020). Kármán, Theodore von. In Encyclopedia of Continuum Mechanics (pp. 1387–1390). Springer.<a href="https://doi.org/10.1007/978-3-662-55771-6_41"> https://doi.org/10.1007/978-3-662-55771-6_41</a> Heppenheimer, T. A. (2007). Facing the heat barrier: A history of hypersonics (NASA SP-2007-4232). National Aeronautics and Space Administration, History Division.<a href="https://archive.aoe.vt.edu/mason/Mason_f/NASASP2007-4232Hypersonics.pdf"> https://archive.aoe.vt.edu/mason/Mason_f/NASASP2007-4232Hypersonics.pdf</a> Source A related resource from which the described resource is derived Theodore von Karman and Raymond Sanger on a trip to Hoover Dam, TVK163.7-6. Caltech Archives and Special Collections. https://collections.archives.caltech.edu/repositories/2/digital_objects/17663 Accessed February 05, 2026. Publisher An entity responsible for making the resource available Caltech Archives and Special Collections 1200 East California Blvd. MC B215-74 Pasadena California 91125 United States of America Date A point or period of time associated with an event in the lifecycle of the resource 1933 Format The file format, physical medium, or dimensions of the resource Photograph https://www.electrifying.collopy.net/files/original/e3a5ba7fa04866b1f2ec088e7a720f5b.jpg f8041e531ac33d55cd887eb7fdcc6ee2 Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Photograph (negative) Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Source A related resource from which the described resource is derived Caltech Archives and Special Collections; Caltech Images Collection, Identifier: 10.46-10 [Accessed February 5, 2026: <a href="https://collections.archives.caltech.edu/repositories/2/archival_objects/111728">https://collections.archives.caltech.edu/repositories/2/archival_objects/111728</a>] Date A point or period of time associated with an event in the lifecycle of the resource Circa 1928 Format The file format, physical medium, or dimensions of the resource Photograph (negative) Available on the archives as a digital image (.jpg) [1935 x 2565 px] Title A name given to the resource Charles C. Lauritsen and Robert A. Millikan Standing Atop the Million Volt X-ray Tube Description An account of the resource This photograph shows a defining moment in the early shape of physics research and study at Caltech: Charles C. Lauritsen and Robert A. Millikan standing atop the million volt X-ray tube at Caltech's High Voltage laboratory (c. 1928). Initially, work at Caltech's High Voltage Laboratory (Hi Volts) powered Los Angeles through long-distance power lines, including lines to the Hoover Dam (Fowler). However, C. C. Lauritsen's move to Caltech in 1926 started a transition towards prolific nuclear physics research at the institute. Using his experience with radios, Lauritsen built the million-volt X-ray tube in 1928, and his electroscope innovation made a statement of Hi Volts' ability to use simple hand-held devices to perform large-scale calculations and phenomenological detections. Lauritsen's high-voltage innovations prompted Millikan to request W. K. Kellogg for financing a new laboratory. (Lauritsen; Fowler) The creation of the million volt X-ray tube brought a paradigm shift in Caltech's physics research. Because these tubes were far more powerful than standard hospital tubes, Caltech was able to explore cancer therapy with high-voltage X-rays. By the 1930s, these medical X-ray technologies moved to the Kellogg Radiation Lab, leaving space for Hi Volts to expand its nuclear physics research and programs prior to World War II. Unfortunately, Kellogg's X-rays were turned off in 1939 due to commercialization of tubes in hospitals. (Lauritsen) While Caltech's labs pivoted towards defense projects during WWII, all war-related work was eventually transferred to China Lake in 1945. With the war did come changes in the goals of the Kellogg lab, with Lauritsen pushing towards low-energy physics, leading towards observation of nuclear reactions in stars. (Fowler) Works Cited <div> <div> Fowler, William A. “Phyphty Years of Phun and Physics in Kellogg.” Engineering & Science, Mar. 1982, resolver.caltech.edu/CaltechES:45.4.Phowler. </div> Lauritsen, Thomas. “Kellogg Laboratory: The Early Years.” Engineering & Science, June 1969, resolver.caltech.edu/CaltechES:32.9.kellogg. </div> https://www.electrifying.collopy.net/files/original/6f0cf8399ea2720cd8d52edb4067209e.jpg 8322fe58bdee982db2aa42fe486cdeea Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Photograph--Nitrate Film Physical Dimensions The actual physical size of the original image 5" x 7" Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Big Creek Transmission Line Description An account of the resource In the early 1900s, Los Angeles and Henry Huntington’s Pacific Electric railway were rapidly expanding. With greater demands of electrical power, Henry Huntington decided to finance the Big Creek project – America’s first extensive hydroelectric project, conceived by John Eastwood [1]. John Eastwood was an engineer who, after surveying the San Joaquin River region, keenly noticed that it was a prime location to leverage the soaring mountain streams [1]. Construction of the Big Creek Hydroelectric project began in 1910 and by 1928, produced 1,600 GWh [6]. In 1921, Big Creek became the first plant in the world designed to transmit power at 220 kilovolts [4]. For comparison, Hoover Dam did not begin transmitting energy until October 1936 [6]. The photo above depicts three of Big Creek’s transmission line towers that carried electricity from Sierra National Forest in Fresno County to the Eagle Rock Substation in Los Angeles through a 241 mile transmission corridor [7]. The sheer might of the towers is visible.These steel lattice towers ranged from 30 to 60 feet tall [2] and upon closer inspection, a greater sense of the elevation and abundance of energy can be recognized. The photograph also notes that one tower is to be removed although the reason for doing so is unclear. Works Cited [1] “100 Years Young: Big Creek Hydroelectric Plant Still Going Strong.” Edison International | Newsroom, https://newsroom.edison.com/stories/100-years-young:-big-creek-hydroelectric-plant-still-going-strong. Accessed 17 Mar. 2026. [2] “Power Lines Around Los Angeles: Isolation, Interconnection, and Aesthetics.” Boom California, 21 May 2020, https://boomcalifornia.org/2020/05/21/power-lines-around-los-angeles-isolation-interconnection-and-aesthetics/. [3] Fox, Donna, Robert J. McEliece, and Babak Hassibi. “An Electrifying Century: An Early History of the Caltech EE Department.” ENGenious, 8 Oct. 2010, engenious.caltech.edu/articles/history-EE-Department-century. Accessed 5 Feb. 2026. [4] Heilbron, J. L., and Robert W. Seidel. Lawrence and His Laboratory: A History of the Lawrence Berkeley Laboratory, University of California Press, 1990. UC Press E-Books Collection, https://publishing.cdlib.org/ucpressebooks/view?docId=ft5s200764&chunk.id=[section identifier]. Accessed 5 Feb. 2026. [5] Millikan, Robert A., and Royal W. Sorensen. Brief for Millikan and Sorensen. Robert A. Millikan and Royal W. Sorensen v. Talma T. Greenwood, Interference No. 56557, United States Patent Office, [Year, e.g., 1928], [Collection Name, e.g., Royal W. Sorensen Papers], [Box 3], Caltech Archives, Pasadena, CA. [6] Ornelas, Gabriela. “Big Creek’s Powerhouse 8 Marks 100 Years of Hydroelectric Power.” Energized by Edison, 8 Oct. 2021, energized.edison.com/stories/big-creeks-powerhouse-8-marks-100-years-of-hydroelectric-power. Accessed 5 Feb. 2026. [7] Record, Historic American Engineering. Big Creek Hydroelectric System, East & West Transmission Line, 241-Mile Transmission Corridor Extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA. Still image. California -- Tulare County -- Visalia, https://www.loc.gov/pictures/item/ca3976/. Accessed 17 Mar. 2026. [8] Sorensen, Royal W., and Hallan E. Mendenhall. “Vacuum Switching Experiments at California Institute of Technology.” Transactions of the American Institute of Electrical Engineers, XLV, Jan. 1926, pp. 1102–07. Semantic Scholar, https://doi.org/10.1109/T-AIEE.1926.5061306. Source A related resource from which the described resource is derived Southern California Edison Photographs and Negatives, Huntington Digital Library Date A point or period of time associated with an event in the lifecycle of the resource 1915-05-15 Format The file format, physical medium, or dimensions of the resource .jpg https://www.electrifying.collopy.net/files/original/45f38d56beef2705d9e125353ef075de.pdf 66f9e74a97e3ed583785ec0061a5052e Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Technical Report on Hydraulic Machinery Laboratory Description An account of the resource In 1933, the greater Los Angeles region saw renewed interest in hydraulics as a source of energy and began laying the foundations for a modern Western water–energy infrastructure. Drawing on a lifelong interest in hydraulics, Theodore von Kármán championed the creation of a hydraulics program at Caltech, arguing it would hold “a unique position in this country and almost in the whole world” (Boronkay, 1985). The document shown here is a technical report describing the establishment and early work of the Cooperative Hydraulic Machinery Laboratory (informally known as the Caltech pump lab), a joint research facility created by Caltech and the Metropolitan Water District of Southern California. In November 1933 the two organizations signed a three-year agreement to design and build the laboratory, which was completed in August 1934 and soon placed into continuous operation. At the time, the laboratory’s primary engineering challenge was addressing problems faced by District engineers in the design of pumping plants for the Colorado River Aqueduct. The aqueduct was planned to deliver roughly 1,600 cubic feet of water per second across nearly 300 miles from the Colorado River to Southern California municipalities. To reach the Los Angeles basin, the water would need to be lifted nearly 1,700 feet, requiring approximately 350,000 horsepower—making it the largest pumping project in existence at the time (Metropolitan Water District of Southern California, n.d.). Under the supervision of von Kármán, R. L. Daugherty, and R. T. Knapp, the laboratory conducted pump studies and precision model tests to guide the aqueduct’s engineering design. Von Kármán himself played a central role in shaping the laboratory’s direction and work and was marked as an irascible personality within the team (Housner, 1984). WORKS CITED: Boronkay, C. (1985). The sleeping giant must stir. Focus on Water, no. 3. Metropolitan Water District of Southern California. Housner, G. W. (1984, July 2, 3, & 11). Interview [Interview]. Conducted by R. Prud'homme. Oral History Project, California Institute of Technology Archives.<a href="http://resolver.caltech.edu/CaltechOH:OH_Housner_G"> http://resolver.caltech.edu/CaltechOH:OH_Housner_G</a> Metropolitan Water District of Southern California. (n.d.). Colorado River Aqueduct virtual tour. Retrieved March 17, 2026, from<a href="https://www1.mwdh2o.com/vr-tours/CRA.html?appid=a5e959ec1c544e1cbeaf63d6ecd56128"> https://www1.mwdh2o.com/vr-tours/CRA.html?appid=a5e959ec1c544e1cbeaf63d6ecd56128</a> Source A related resource from which the described resource is derived Report on Hydraulic Machinery Laboratory, Box: 107, Folder: 10. Theodore von Kármán Papers, 10143-MS. Caltech Archives and Special Collections. https://collections.archives.caltech.edu/repositories/2/archival_objects/46089 Accessed March 17, 2026. Publisher An entity responsible for making the resource available Caltech Archives and Special Collections Repository 1200 East California Blvd. MC B215-74 Pasadena California 91125 United States of America Date A point or period of time associated with an event in the lifecycle of the resource 1933 Format The file format, physical medium, or dimensions of the resource Technical Report, Physical Document https://www.electrifying.collopy.net/files/original/c4a2ac41ca93ba20b1133028a8434b24.jpg 965af64de8d81f968a84607146596bb9 Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Colorado River Aqueduct Map Description An account of the resource This map of the Colorado River Aqueduct was produced by the Metropolitan Water District of Southern California in April 1936. Stretching nearly 300 miles from the Colorado River to the Los Angeles basin, the aqueduct crossed deserts, valleys, and mountain ranges through an interconnected system of canals, tunnels, reservoirs, and pumping stations. Engineering profiles recorded key hydraulic conditions along the route, including static head variations of roughly 235 to 320 feet and internal pressures approaching 160 pounds per square inch (Caltech Archives and Special Collections). As such, the aqueduct relied on massive welded steel pipelines nearly fourteen feet in diameter and a series of pumping plants capable of lifting water across large elevation changes. Designing such a system required precise understanding of fluid flow, pressure losses, and pump performance — questions that became a focus of research at the Caltech pump lab. Kármán's work specifically included comprehensive studies of pumps with different specific speeds and precision acceptance tests of model pumps submitted by contractors for use at locations along the aqueduct route using scaled hydraulic models built and maintained at Caltech (Caltech Archives and Special Collections). This work formed part of a broader program of government-funded collaboration that contributed to major Western water infrastructure projects, including Hoover Dam, Grand Coulee Dam, and the Feather River Project (Von Kármán et al., 1933). WORKS CITED: Theodore von Kármán Papers, 10143-MS, Box 107, Folder 5. Caltech Archives and Special Collections. Retrieved March 17, 2026, from<a href="https://collections.archives.caltech.edu/repositories/2/archival_objects/46084"> https://collections.archives.caltech.edu/repositories/2/archival_objects/46084</a> Von Kármán, T., Bauman, P., Rowe, R. R., Prandtl, L., Pearce, C. E., Brahtz, J. H. A., Heilbron, C. H., Bakhmeteff, B. A., & Mononobe, N. (1933). Von Kármán on pressures on dams during earthquakes. Transactions of the American Society of Civil Engineers, 98(2), 434–470.<a href="https://doi.org/10.1061/TACEAT.0004491"> https://doi.org/10.1061/TACEAT.0004491</a> Source A related resource from which the described resource is derived Metropolitan Water District of Southern California. (1936, April). Colorado River Aqueduct [Map]. Huntington Library. https://catalog.huntington.org/record=b1269824 Publisher An entity responsible for making the resource available Huntington Digital Library Date A point or period of time associated with an event in the lifecycle of the resource April 1936 Format The file format, physical medium, or dimensions of the resource Digital Image https://www.electrifying.collopy.net/files/original/2282de192b0f114285c51cb37b7fd137.jpg 737ad52cc897528d30e8b6018d4a01f3 https://www.electrifying.collopy.net/files/original/72508d59f9c43b07dede5e0ca1deb5c6.jpg 76c80d50e92793596e5aa230414229af https://www.electrifying.collopy.net/files/original/e680e2db9f2a9941d6e599eaef1bf7cd.jpg 566e62e401c1919c7362eacbf7db6853 Still Image A static visual representation. Examples include paintings, drawings, graphic designs, plans and maps. Recommended best practice is to assign the type Text to images of textual materials. Original Format The type of object, such as painting, sculpture, paper, photo, and additional data Typed memorandum, 3 pages Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Memorandum Regarding Kellogg Radiation Laboratory Research, Future Plans, and Caltech's Physics Curriculum Description An account of the resource Lauritsen and Fowler’s 1948 memorandum defines the Kellogg Lab’s post-WWII pivot from high-voltage X-rays toward fundamental nuclear research. This transition is clear when we look at Caltech's 1942 Big T, a student yearbook prior to end of WWII. It emphasized the connection from the High Voltage Laboratory to the broader LA community, like Hollywood recording studios, through Westinghouse and the Southern California Edison Company (California Institute of Technology). However, this emphasis on high-voltage transmission and X-rays faded, as seen through the Kellogg Lab's new goals shown in the memorandum. Robert Millikan failed at sustaining X-ray medical technology research at Caltech - a key focus of the Kellogg Lab - due to funding challenges and medical X-ray commercialization (Holbrow). Soon afterwards, the memo shows how the lab shifted towards stellar energy research. The institution as a whole responded through the formalization of physics courses like Ph 12abc and Ph 109abc that moved away from high-voltage transmission and urban electrification towards atomic discovery. Works Cited <div> <div> California Institute of Technology. The Big T, 1942 - CaltechCampusPubs. resolver.caltech.edu/CaltechCampusPubs:20111024-135709577. </div> Holbrow, Charles H. “The Giant Cancer Tube and the Kellogg Radiation Laboratory.” Physics Today, vol. 34, no. 7, July 1981, pp. 42–49. https://doi.org/10.1063/1.2914646. </div> Source A related resource from which the described resource is derived Caltech Archives and Special Collections; California Institute of Technology Historical Files, Series A: Academic Division & Programs, Division of Physics, Math & Astronomy, Box A12, Folder 10. [Accessed March 17, 2026: <a href="https://collections.archives.caltech.edu/repositories/2/archival_objects/104749">https://collections.archives.caltech.edu/repositories/2/archival_objects/104749</a>] Date A point or period of time associated with an event in the lifecycle of the resource July 8, 1948 Format The file format, physical medium, or dimensions of the resource Typed memorandum (3 pages) Scanned as digital image (.jpg)