Slide rule makers

Slide rule makers	There are still some slide rules being made today - as far as I can tell only specialised ones. This makes sense as in many specialised applications the relationhips are not linear and, in some cases, non-logarithmic. This means that they cannot be solved using multi-function electronic calculators.
M. H. Mear & Company	This company based in England makes almost thirty different specialised slide rules. In many cases the relationships represented by the special scales are ones which cannot easily be solved by calculators. A summary of the catalogue can be found here.	The company's contact details are: M H Mear and Company Ltd. Calculator Designers Ramsden Mills, Britannia Road, Milnsbridge, Huddersfield, W. Yorkshire, England HD3 4QG Telephone: 01484 648181 Fax: 01484 657098 Email: kath@mhmear.com Their web site is at: http://www.mhmear.com/
IWA, Stuttgart, Germany.	This company makes a wide range of specialised slide charts and slide wheels. They cover the following areas: Chemistry and Pharmaceuticals Construction Industry Construction of Machines and Equipment Electrotechnical Uses Heating and Ventilation Equipment Heat-Treating and Welding Equipment Metal Processing Motor and Car Industry Other Applications Pipes, Flanges, Screws Textiles and Textile Machinery Weight Data Wood	The company's web site is available in English, German and French. The address for the English version is: http://www.iwa.de/3-E/fr-main-E.htm
Calcoolator Co	This slide chart enables calculations of pipe sizes for cooling systems in English or Metric units This appears to be the company's sole product. The site was copyrighted in 1999 but I don't know when the rule itself was developed.	www.calcoolator.com
Feild's Wheel	Also known as Feild's Hydraulic Calculators for calculating the flow of pipes when flow is under gravity. Can be used when pipe is full or part-full, radii from 4 to 72 inches and slopes from 0.04 to 10.0 feet per hundred.	http://feildwheel.googlepages.com/