machining, founding, optical glass casting and lens grinding. Aspects of the telescope design were, at the time of construction, considered innovative and otherwise only used in professional installations, e.g.: the control of airflow with the telescope tube; the use of clocks to synchronise the motor drive with earth's rotation, full motor control of telescope and dome positioning while observing. The planetarium started in the late 1950s, while designed with reference to the Zeiss planetariums, is of Ken Beames' own design, built from first principles. It was the first and possibly only attempt to design and construct such a mechanism in Australia and represents a major technical achievement. Other well known planetariums in Australia include the HV McKay Planetarium, an imported Zeiss planetarium installed at the Museum of Victoria in 1965, the Launceston Planetarium, another Zeiss projector installed in 1969 and the South Australian University Zeiss planetarium installed in 1972. Ken Beames' workshop with its tools and equipment remains intact and includes work pieces, custom made tools, machinery and jigs which demonstrate practical solutions to problems encountered, including the need to mass-produce high precision items, e.g.: sighting telescopes, lens' and parabolic mirrors. All items of Ken Beames' construction, both the central objects such as the planetarium, telescopes and clocks, and the tools he constructed to help make these objects, demonstrate very high levels of multidisciplinary craftsmanship. The moveable collection of items Beames constructed for private use or as gifts demonstrate high technical achievement and are aesthetically distinctive. The range of items runs from candle holders, brass jewellery boxes and cast bronze vases to detailed miniature working artillery "potato guns", brass grandfather clock, and a book made with brass pages – Rubaiyt of Omar Khayym. This intact complex is instructive in the study of mechanical & electrical engineering and optics of the mid 20th century and exemplifies the astronomical and general engineering technology and methods of that era. The place has a strong or special association with a particular community or cultural group in New South Wales for social, cultural or spiritual reasons. The Linden Observatory is of State social significance afor the long and productive association that Ken Beames shared with amateur and professional astronomers. Many individuals and groups visited the site to learn from Ken Beames. The depth and variety of his demonstrated skills in engineering and telescope-making made a visit to Linden an inspiring experience. Visitors to the site