Path:news.helsinki.fi!news.csc.fi!news.eunet.fi!EU.net!news.sprintlink.net!cc.iu.net!news From: blombard@iu.net (Bob Lombardi) Newsgroups: sci.astro.amateur Subject: Amateur Telescope Maker's Resource List, 1/2/96 Update Date: 2 Jan 1996 14:08:43 GMT Organization: Organized? I can't even find my car keys Lines: 600 Message-ID: <4cbe9b$s6@cc.iu.net> NNTP-Posting-Host: netport-35.iu.net Mime-Version: 1.0 X-Newsreader: WinVN 0.93.14 * * Amateur Telescope Maker's Resource List * * Last revised: 1/1/96 Now in it's Fifth year. Maintained by: Bob Lombardi, blombard@iu.net Fellow sci.astro and sci.astro.amateur readers. Here is the latest version of the ATM Resource List. This list is archived in at least the following WWW sites: http://garnet.acns.fsu. edu/~swingree/atmres.html http://www.dnai.com/~wperko/dobson.htm http://www.rahul.net/resource It is available in the America Online Astronomy area. It is available via ftp from: ftp://ftp.rahul.net/pub/resource It may be obtained via email from: resource@rahul.net And, finally, I mail it out regularly, as well. Changes in this version include: New listing for TL Systems under part V. New books for the beginner (well, one new and one old book). Minor updates to the UK Supplier list (thanks to Steve, sft@aegis1.demon.co.uk) If you have any experience with these companies, new addresses or phone numbers, or any other feedback, please email me to get your updates included. Good, as well as bad, experiences are always welcome. A particular weakness of this list is that it has a strong North American, and especially US, bias. This is stictly due to my resources in finding companies to list. I hope that the list of UK sources helps to ease this problem. As this list is at its best when seen by as many as possible, feel free to archive it, post it on a WWW home page, or add it to a CD Rom collection. Please do not modify it. If any modifications are needed, contact me to ensure that everyone sees the latest corrections. I must issue the std disclaimer: I have nothing to do with any of these companies, other than being a satisfied customer of a few, and an ex-customer of some others. The list is not complete, but does cover the most needed things. Here goes. * * * * * * * * * * Amateur Telescope Maker's Resource List Part One: North American Sources I. Mirror Making Kits and Supplies: The following companies sell telescope making supplies, including mirror blanks, lens blanks, abrasives, polishing agents, and other helpful accesories. US Glass Fab Inc., 257 Ormond St, Rochester, NY 14605, (716) 262-4000. Blanks, including Sitall Newport Glass Works, Ltd., 2044-D Placienta Ave., Costa Mesa CA, 92627 phone 714-642-9980 Supplies pyrex blanks, tapered (SCT) blanks, lens blanks, colored filter blanks, plus abrasives and pitches. It should be mentioned that sci.astro.amateur opinions of Newport run somewhat negative. Palomar Optical Supply, P.O. Box 1310, Wildmar, CA 92395 phone 619-631-2835 voice, 619-631-2957 Fax Mirror kits and abrasives. Sells the old standard pyrex blank/plate glass tool kits. Abrasives, pitch. See their listing under Commercially made optics (below) for more info. Salem Distributing Company, Inc. Box 25566 Manor Station, Winston-Salem, NC 27114, 800-234-1982 Originally the source of the opthalmic polishing pads discussed in S&T's ATM column, they now sell a complete line of grits and polishing agents. Very friendly. These folks sell primarily to the eyeglass industry. United Lens Co., Inc., South Bridge, Mass. 01550 617-765-5421 United is a major producer of optical glass for industry. They have been reported as a source of pre-rough shaped blanks in unit quantities, and refractor objective blanks. Willmann-Bell, Inc. P.O. Box 35025, Richmond, VA 23235 phone 804-320-7016 catalog $1 Consistently good recommendations on the net. Pyrex blank/pyrex tool kits, ceramic tiles for tools, plus a complete line of pitch and abrasives. Canada Eftonscience Inc., 3350 Dufferin St., Toronto, Ont. M6a 3A4 ph 416-787-4581 catalog $6 Telstar, 2130 Primate Rd, Mississauga, Ontario ph 905 277 1113 mirror kits, Pyrex, grit, pitch, etc, but does not supply plate tools. Also handles sital blanks, Cass kits, Maksutov kits, up to 12.5 inch, and finished mirrors in Newt, Cass, Mak, etc. Prices in US funds. II. Mirror Coating Services Denton Vacum, 1259 N. Church Street, Moorestown, NJ 08057 609-439-9100 Fast turnaround. Can do up to 30" Evaporated Metal Films, 701 Spencer Road, Ithaca, NY 14850 607-272-3320 P.A.Clausing, Inc. 8038 N. Monticello Ave. Skokie, IL, 60076 708-676-0330 Voice, 708-676-2930 Fax, e-mail: hclaus@interaccess.com, Beral, Silver, Gold, Aluminum, Copper, Rhodium, (most other evaporable metals) and Overcoatings, Fast turnaround available. Can do up to 90" diameter, up to 1 ton weight (3 tons next year). Precision Applied Products, 418 Rumsey Place, Placentia, CA 92670 714-738-4775 In addition to standard and enhanced mirror coatings, they offer MgF2 for refractor lenses and windows. QSP Optical Technology. 1712-J Newport Circle, Santa Ana, CA 92705 (714)-557-2299. Southwest Optical Technologies, PO Box 65867, Tucson, AZ 85728 (520)-881-0863. Vacuum coatings by Lynn Hepburn. III. Telescope Making Books and publications Periodicals _ATM Journal_. The Amateur Telescope Makers Association (ATMA) 17606 28th Ave. S.E., Bothell, WA 98012. This has the "look and feel" of the old _TM_. Membership is $20. _AMATEUR ASTRONOMY_. 2111 Whitield Park Ave, Sarasota, FL 34243 (813)-758-9890 Edited and published by Tom Clark and Tectron. Now in its second year. Coverage of Amateur Astronomy events, issues, people, and telescope making. _Astronomy_ occasional material for TM's. Check your bookstore or newstand _Sky and Telescope_ monthly column for TM's. Again, check your newstand, or mall bookstore Books Beginner "Build Your Own Telescope", Richard Berry, Pub by Kalmbach Publishing (pub. of Astronomy) ISBN 0-684-18476-1 $24.95 + $1.50 s&h. Now in the Willmann-Bell catalog. "How to Make a Telescope", Jean Texereau, 2nd ed., Pub and sold by Willmann-Bell, ISBN 0-943396-04-2, $19.95 +$1 s&h, address above (under tm supplies) "Making and Enjoying Telescopes", Robert Miller and Kenneth Wilson, Sterling Publishing, 1995, ISBN 0-8069-1277-4, $24.95 at bookstores. 6 telescope projects using commercial optics, superb photos and illustrations. Written for absolute beginners. "Making Your Own Telescope", Allyn Thompson, Sky Publishing, 1947, 1973, ISBN 0-933346-12-3, $ 14.95 + s&h from Willmann-Bell (also available from Sky Publishing). Dated, but lots of solid info and advice. Concentrates on a 6" f/8. Advanced "Advanced Telescope Making Techniques", Volumes 1 and 2, ISBN 0-943396-11-5 (vol 1) and 0-943396-12-3 (vol 2), pub by Willmann-Bell, address above "Telescope Optics: Evaluation and Design", Rutten and van Venrooij, ISBN 0-943396-18-2, Willmann-Bell, companion software available "Microcomputer Control of Telescopes", Trueblood and Genet ISBN 0-943396-05-0, Willmann-Bell "Prism and Lens Making" F Twyman, ISBN 0-85274-150-2, pub by Adam Hilger, NY, 1988 (corrected reprint) "Astronomical Optics" Daniel J. Schroeder, Academic Press, 1987 ISBN 0-12-629805-X, Advanced undergraduate text with loads of info. Available from Willmann-Bell Other Videos: * "How to Make a Telescope", John Dobson, 2hr Video Dobson Video, PO Box 460915, San Francisco, CA 94146-0915 Make check to "Dobson Astro-Initiatives" Cost: $43 (includes postage and handling) (Calif residents add $3.40 sales tax) From the ad, "For the first time on video, John Dobson shows how you can build your own high-power, low-cost telescope. The 2 hour video is a complete step-by-step guide, covering telescopes 8" to 16" and larger." * "Collimation of Newtonian Telescopes" by Rich Combs and Alan Gorski Richard Combs, 5151 Greentree Ct., Pleasanton, CA 94566, Cost: $20, shipping included in the US. A limited quantity of the tapes is also available from LUMICON. A 37 minute step by step guide to collimation principles and techniques. Targeted primarily at the Newtonian type reflector. Extensive description and use of collimation tools. Tips, tricks, and many special mock-ups intended to aid understanding and help improve your telescope's performance. IV. Commercially-Made Optics A. Jaegers, 6915 Merrick Rd., Lynbrook, NY 11563 -or- 11 Roosevelt Ave. Valley Stream, NY 11581 516-599-3167 Specializes in refractor lenses and reflector mirrors up to 6". "Lowest national price". It is best to send them a fax of your requirements for a lens, as they have no current catalog. FAX 516-872-8112. The Astronomy Shoppe, 15836 N. Cave Creek Rd, Phoenix, AZ (602)-971-3170. Custom mirrors. Clear Star Optics, 4193 Tallmadge Road, Rootstown, OH 44272 (216-325-1722) Newtonian Mirrors, also flats. D & G Optical, 6490 Lemon Street, East Petersburg, PA 17520 717-560-1519 Refractor objectives, apochromatic (5.1") and achromats (5 -12") Refractor Tube Assemblies (OTAs) 5" to 12" Classical Cassegrain sets and OTAs. Also parabolic mirrors through 20". Refigures finished mirrors. E & W Optical Inc. 2420 E. Hennepin Ave., Minneapolis, MN 55413 612-331-1187 Edmund Scientific, dept 10B1, N919 Edscorp Bldg, Barington, NJ 08007 Edmund is not the astro company they once were, but they do carry a lot of lenses and some other optical components. Enterprise Optics, P.O. Box 413, Placienta, CA 92670 714-524-7520 Newtonian and Cassegrain Optics, 6" to 24" Elliptical flats to 6". Great Plains Instruments, David Harbour, 610 N 14th, Enid, OK 73701 (405)237-7057. Mirror grinding and finishing (no coating), mirror refiguring, testing and evaluation. Galaxy Optics, P.O. Box 2045, Buena Vista, CO 81211 719-395-8242 A very well respected name in finished mirrors. Iowa Scientific Optical, 4231 Northwest Drive, Des Moines, IA 50310 (515-255-0166) Newtonian and Schiefspigler Optical sets, flats, mounts, tube assemblies and complete telescopes. J.C. Wilkinson Optics 303-499-7662 (Boulder, Colorado) Jerry Wilkinson, senior optician for seven years for Galaxy Optics. Primarily refiguring services, but will also quote finished mirrors. He will figure mirrors from 6" to 14.5". JSL Perpetual Technology, Inc., 275 East 100 North, P. O. Box 51 Willard UT 84340, (801) 723-5568, Primary mirrors 6-30", focusers, eyepieces and mounts. Lumicon, 2111 Research Dr., Suite 5, Livermore,CA 94550 510-447-9570 NOVA Optical Systems, P.O. Box 80062, Cornish, UT 84308, (801) 258-5699. 6 to 25" Newtonian Mirrors, f4-f10. Orion Telescope Center, 2450 17th Avenue, PO Box 1158 Santa Cruz, CA 95061 800-447-1001, Newtonian primaries, 6 - 12.5", & secondaries. Palomar Optical Supply, P.O. Box 1310, Wildmar, CA 92395 phone 714 678-5393 In addition to their mirror kits, they also supply parabolic mirrors, "planetary optical sets" (long f-ratio primaries) elliptical secondary flats to 6", and round flats to 8". Parks Telescope Co., c/o Scope City, 679 Easy Street, Simi Valley, CA 93065 (805) 522-6646, Newtonian primary mirrors 4.5-16", secondaries. These are the mirrors used in Parks' telescopes. Pegasus Optics RR 5, Box 502, Huntsville, AR 72740, Phone: (501) 738-1650 9am-9pm 16 to 28" Mirrors, Lifetime warranty, test/certs for all mirrors sold. Precision Applied Products, 418 Rumsey Place, Placentia, CA 92670 (714)-738-4775 or 800-575-4775 Refractor lenses, 5" to 12" (this is the same company listed in coatings, above). Star Instruments, PO Box 597, Flagstaff, AZ 86002 520-774-9177 United Lens Co., Inc., South Bridge, Mass. 01550 617-765-5421 University Optics, P.O.Box 1205, Ann Arbor, MI 48106 800-521-2828, sells a small line of mirrors in addition to the other supplies listed in part 5. V. Telescope Parts (finders, focusers, eyepieces, etc., etc.) The Astronomy Shoppe, 15836 N. Cave Creek Rd, Phoenix, AZ (602)-971-3170. Custom mirrors and "Bigfoot" mounts. AstroSystems, Inc., 5348 Ocotillo Ct., Johnstown, CO 80534 303-587-5838, Primarily parts for big Dobsonians. Truss tubes, mirror cells, formica, secondaries, focusers, huge elevation bearings (like on the Obsession scopes), and more. Ceravolo Optical Systems, Peter Ceravolo, Box 1427, Ogdensburg, NY 13669 (613) 258-4480 Supplies for Interferometry, testing for ATM's, instruction booklets, interferometer parts and analysis software. Crazy Ed Optical, P.O. Box 110566, Campbell, CA 95011-0566 Phone or Fax: (408) 364-0944. Dobsonian parts: Ebony Star formica, teflon, tube trim. Spiders, diagonal holders and mirrors, focusers, finder (Telrad and Conventional), LED lamps and flashlights, charts, and even more. Edmund Scientific, address above Equatorial Platforms, 11065 Peaceful Valley, Rd., Nevada City, CA 95959 catalog $2 Poncet platforms. Hollywood General Machining (Scott Losmandy) Hollywood, Ca. 213-462-2855. Losmandy mounts are sold by Celestron and other big companies. He reportedly sells direct as well. Kenneth Novak & Co., Box 69T, Ladysmith, WI 54848 715-532-5102 Generally regarded as one of, if not _the_, best makers of cells, spiders, and other mechanical parts. Jim's Mobile Inc., 810 Quail St. Unit E., Lakewood, CO 80215 Orders 800-247-0304, info 303-233-5353, Better known as JMI, the makers of the NGT-18 telescope. They carry one of the largest lines of focusers on the market, including motorfocusers. All JMI focusers are Crayford type, often considered the best. They also carry NGC Max computers. Lumicon, address above Motion Control Systems, P.O. Box 19632, Portland, OR 97280, 503-244-0503, Telescope Mounts and accessories, catalog $2 Opti-Craft Machining, 33918 Macomb, Farmington, MI, 48335, (810)- 476-5893. "Quality clock drives and telescope accessories", according to the catalog. Highly precise gears, worm drives. Orion Telescope Center, 2450 17th Avenue, PO Box 1158 Santa Cruz, CA 95061 800-447-1001, Orion has gradually become a complete supplier for ATMs: spiders, diagonals, focusers, mirror cells, finders, filters, eyepieces, barlows, etc.. One of America's largest dealers. Parks Telescope Co., c/o Scope City, 679 Easy Street, Simi Valley, CA 93065 (805) 522-6646, markets parts used in their telescopes; miror cells, spiders, focusers, mounts, clock drives & correctors, eyepieces, etc. Photon Instument, Ltd. 122 E. Main St, Mesa, AZ 85201 (602)-835-1767 or (800)-574-2589. Restorations, optical testing, unobstructed reflectors, as well as custom telescope manufacturing SOFT-TEC Systems, 9333 Crowley Rd., Suite A, Fort Worth, TX 76134-5904 (800) 354-1256 / (817) 293-8446 / fax (817)293-8606 sells "SKY PROBE 1000" Telescope Positioning System, SW for PC. motor driver electronics and cables, hand control, stepper motors Stardrive Systems, 233 Bannock St., Denver, CO 303-722-4104 Mirror cells, 4-1/4 to 20" TL Systems, 2184 Primrose Ave., Vista, CA 92084, ph/fax-619-599-4219 Equatorial platform and binocular viewer kits. email: tlsystem@ix.netcom.com, http://www.nbn.com/people/sunspot/ tlsystems Tech2000, 3349 SR99 S, Monroeville OH 444847, (419) 465-2997 Dob Driver II computerized drive systems for commercial or homemade Dobsonians. Tectron Telescopes, 211 Whitfield Park Avenue, Sarasota, FL 34243 (813) 758-9890 Parts as well as complete instruments Televue, 100 Route 59, Suffern, NY 10901 (914) 357-9522 University Optics, P.O.Box 1205, Ann Arbor, MI 48106 800-521-2828, Focusers, finders, mirror cells, CCD camera kits for the Cookbook Camera, telescope tubes. VI. Miscellaneous American Surplus, Inc. 601 Linden Place, Evanston, IL 60202 (copier lenses for finder scopes, heat ropes for dew- removal, and lots of weird stuff) (formerly Jerryco) Hastings Irrigation Pipe Co., P.O. Box 728, Hastings, NE 68902 (402)463-6633 Supplier of aluminum irrigation tubing . One reader "obtained some that's .064" wall thickness and comes in 12, 10, 8, 7, 6, 5, 4, 3" diameters. The tubing is pretty cheap (the 6" by 4' was $12.24 + shipping (8/94)) and the company ships COD" Small Parts, Inc. 13980 N.W. 58 Ct. P.O. Box 4650, Miami Lakes, FL 33014-0650 305-557-8222, Small gears, tubes, nylon, teflon, screws, setscrews, taps, tools and enough other small mechanical parts to glaze over the eyes of any model builder. If you can't find it here, it doesn't exist! Part Two - Europe ========================================================================== Anchor Surplus Cattle Market Nottingham UK Tel: +44-(0)115-986-4902 An absolute treasure trove for the ATM! Military surplus optics (lenses, eyepieces, prisms, beam-splitters, etc), many unused, at ridiculously low prices. Must visit. AWR Technology 67 Thornbridge Road Deal Kent CT14 9DZ UK Tel: +44-(0)1304-365918 Fax: +44-(0)1304-365737 Drives and controllers for synchronous and stepper motors. Beacon Hill Telescopes 112 Mill Road Cleethorpes South Humberside DN35 8JD UK Tel: +44-(0)1472-692959 Many accessories and mirrors (Hinds), pitch, grinding powders, glass blanks, tubing, drives, cells. Make telescopes to order. Also equatorials (German and fork). Aluminising. Quoted delivery times are unreliable. Braithwaite Telescopes 9 Manse Brae Dalserf Lanarkshire ML9 3BN Scotland UK Tel: +44-(0)1698-881004 Manufacture their own telescopes and German equatorial mounts. Also offer accessories and mirrors (Oldham). Aluminising. Broadhurst, Clarkson and Fuller Ltd. Telescope House 63 Farringdon Rd UK London EC1M 3JB Tel: +44-(0)171-405-2156 Tel: +44-(0)171-405-0448 Fax: +44-(0)171-430-2471 Mirrors (Hinds), focusers, observatory domes. Reliable and knowledgeable source of commercial telescopes and accessories. Carl Lingard 89 Falcon Crescent Clifton Swinton Manchester M27 8JP UK Tel: +44-(0)161-794-8650 Components for ATMs: Mirrors, tubing, equatorial kits, cells, drives. Falcon Optical Services Unit 4 Sea Vixen Industrial Estate Wilverley Road Christchurch Dorset BH23 3RU UK Tel: +44-(0)1202-473442 Polishing pads. David Hinds Unit 34 The Silk Mill Brook Street Tring Herts HP23 5EF UK Tel: +44-(0)1442-827768 Fax: +44-(0)1442-890763 David Hinds mirors have a great reputation! Also imported telescopes (which he checks before selling!) and accessories. IR Poyser (Engineering) 15 Dale Rd Rochester Kent ME1 2JP Tel: +44-(0)1634-401220 Object glasses and lots of optical oddments for ATMs, including military surplus. Nigel Wakefield 37 Glebelands Radstock Bath BA3 3SU UK Tel: +44-(0)1761 435137 Email: telescopes@phred.demon.co.uk Mirrors to order and eyepieces. Orion Optics Unit 21 3rd Ave Crewe Gates Industrial Estate Crewe Cheshire CW1 1XU Tel: +44-(0)1270-500089 Fax: +44-(0)1270-251213 Accessories (including mirrors) for ATMs. Also make telescopes which have an excellent reputation. Delivery times are unreliable. SCS Astro South View Runnington Wellington Somerset TA21 0QW UK Tel: +44-(0)1823-661544 Fax: +44-(0)1823-661545 Range of CCD cameras, some accessories, Russian telescopes. Starlight Express FDE Ltd. Tel: +44-(0)1734-342600 Fax: +44-(0)1734-320745 CCD cameras and accessories with an excellent reputation. True Technology Ltd Woodpecker Cottage Red La Aldermaston Berks RO7 4PA UK Tel: +44-(0)1734-700777 Fax: +44-(0)1734-701661 CCDs, filters, some accessories, imported telescopes. Vacuum Coatings 66 Barrett Road Walthamstow London E17 UK Tel: +44-(0)181-520-5353 Aluminising, mirrors, eyepieces, grinding powders. ========================================================================== Europe Astronomische Materialzentrale SAM, Postfach 715, CH-8212 Neuhausen a/Rhf., Switzerland, 41 (0)53 22 3869, 41 (0)53 22 5416 (where the 0 is only dialed internal to Switzerland, 41 being the country code). Complete mirror kits. Also sells finished mirrors, eyepieces, focusers. Catalog approx $2. The catalog is in German, but phone personnel apparently speak English and other languages. Summary and Advice for the Beginner Before you start, get the Willmann-Bell catalog. It's a small newspaper filled with interesting books, and they sell mirror making supplies. Get Richard Berry's book "Build Your Own Telescope". Check out the chapters on homebrew optics. If you can't find an experienced tele- scope maker to help you, start small. It will take you less time to grind and polish a 6" f7 or f8 mirror and then do your fantasy 12" (or 17, or whatever) than to start with the big one. Even if you finish your 6" scope and then never use it. If you have someone to turn to for help, an 8" f7 or 8 makes a good starter scope. If you're going to work on your own, get Texereau's book. Between the two of them you can figure out what is going on. Use a template to judge your rough curve. Cardboard is ok, you'll learn where the uneven spots are in its shape. As you progress through the grinding stages, spend more time with the tool on top. In the finest grades the tool is almost always on top. Say one wet with mirror on top to 10 with tool on top. This concentrates the work on the edge, where you need it most. The outermost edge contains most of your mirror's area, the innermost circle is covered by the diagonal. (source for this idea, TM#6) I like mats for molding the pitch lap. John Dobson uses a thin wooden dowel pressed into the hot pitch. One of the most common flaws in a first mirror is inadequate polish. Either of these techniques will help you get a better lap. In addition, you should micro-facet your lap with fiberglass screen (I got mine at the local building supply house). It can save you an hour on even a 6 inch mirror. The opthalmic polishing pads that have been mentioned in S&T and other places polish extremely fast. I would recommend them only for someone who has already polished out a mirror on pitch. On the other hand, I wouldn't dream of doing a mirror over 10" without them. You will need to monitor the surface with frequent Ronchi tests (just as they polish fast, they can also turn an edge extremely fast) and then follow the pads with a half hour to an hour on pitch. You should test your mirror more than one way. The Ronchi test, using a grating of 85-100 lines/inch, is excellent for checking the surface during polishing to ensure you're not turning down your edge. It's also bright enough to do in normal room light, unlike the Foucault test. The star test can be a very sensitive way to determine the overall figure of your mirror, but requires a tube and all of your other components to test with. It may be even more important than the Foucault test, but do the Foucault or similar test anyway; it's the most accessible way to get the overall correction in waves that you want. If you plan to buy commercial optics, learn to test a mirror anyway. You can use the star test or a Foucault tester. University Optics sells a nice kit, if you don't want to make one. One of the advantages of grinding your own mirror is that you build a tester and learn to use it as part of the process. Of course, you also have control of when it's "good enough", and are not under the production pressures that a commercial mirror maker is. Commercial mirrors vary in quality quite a bit, and even the best companies will occasionally let one slip by. So make sure you test your mirror and make sure you understand the test. Don't expect an f4 Dobsonian mirror to be optical perfection; it is quite difficult to achieve diffraction limited performance from an f ratio this short. Of course if you're _paying_ for diffraction limited, that's something else! There you have it. Enough references to get the beginner started. If you find this list useful, or if you find it lacking, I'd appreciate feedback. Clear skies... Bob -- Bob Lombardi WB4EHS in Melbourne, FL o \---\---\ blombard@iu.net or blombard@freenet.fsu.edu /\ | Telescope making, optics, astronomy, piano, bicycling -\ 7 & radio | I've run out of things I can say in 4 lines. (*)/(*) |