标签: electromagnets

On the one hand, I would say that I'm generally an upbeat sort of person. I tend to look for the silver lining in most clouds and I'm definitely a full-fledged member of the "glass half full" fraternity. (I even have the t-shirt and know the secret handshake.) On the other hand, some things do tend to niggle at me. One of these things is the sneaking suspicion that we are in danger of losing track of how to do things at the most fundamental levels. If you go back to 1900, for example, there were legions of craftsmen who could create the most wondrous artifacts out of sheet metal by hand. These days, by comparison, we have incredibly sophisticated computer-aided design tools and computer-controlled fabrication machines that can do a lot of the "thinking" and the manufacturing for us—the downside is that it's becoming almost impossible to find anyone who is capable of doing this sort of thing without having access to these tools and machines. Is this really important? Does it really matter? Well, actually I think it does, although I find it difficult to articulate why (I'd appreciate any help you would care to give here). Until recently, one of the things that used to cheer me up was the presence of a small Internet-based company called Lindsay's Technical Books. These tomes were billed as "Exceptional technical books for experimenters, inventors, tinkerers, mad scientists, and 'Thomas-Edison-type'". I've ordered a few odd items from them over the years (some of these items were very odd indeed), and I still have their January 2007 Catalogue #637 in my office, as shown below:   The idea was that Lindsay and friends gained access to old engineering books that were no longer under copyright and were now in the public domain, and they re-printed them on-demand for a modest fee. For example, one series of books explained how to go about building a machine shop from scrap. This started with the construction of a small charcoal foundry, and then led onwards and upwards to building a metal lathe, a metal shaper, a milling machine, a drill press, and so on and so forth. Just glancing through this old catalogue again and cherry-picking a few items for your delectation and delight, we see books on topics like the design of magnets and electromagnets, armature winding and motor repair, making neon signs, electroplating, silver printing (making photographic prints on paper with egg whites), making casts, building a forge, making your own woodworking tools, blacksmithing, working with wrought iron, building a pipe bending machine, working with sheet metal, building a wind turbine, building your own generators and inverters to generate your own electricity, building an alcohol-producing still, the distillation and rectification of alcohol, glass working, barrel making, manufacturing your own bricks and tiles... and the list goes on, and on, and on! In fact, while glancing through this old catalogue as I was penning this column, I ran across one item that is of particular interest to me at the moment with regard to a current hobby project. This little beauty is the 1893 printing of a book titled Five Hundred and Seven Mechanical Movements by Henry T. Brown. Actually, if the truth be told, the full title of this book (the original version of which came out in 1868) is as follows: Five Hundred and Seven Mechanical Movements: Embracing all those which are most important in Dynamics, Hydraulics, Hydrostatics, Pneumatics, Steam Engines, Mill and other Gearing, Presses, Homologous, and Miscellaneous Machinery; and including many movements never before published and several which have only recently come into use. Wow! Now that's what I call a title! As I said, this type of thing is currently of interest to me, so I immediately bounced over to Lindsay's Technical Books website at www.lindsaybks.com . Oh the shock! Oh the horror! They've retired, and Lindsay's Technical Books is no more. Suffice it to say that I was not wearing my happy face. But then I thought to myself: "Maybe a copy of this book is still available somewhere in the world," so I had a quick Google (it's alright, no one was looking) and I was amazed to find that there's a paperback reprint version on Amazon. Even better, it turns out that Google has a digitized copy you can download as a PDF for free by clicking here . I just did so to discover that this little beauty is all I had hoped for and more. Here's an example page:   I cannot wait to spend some quality time rooting through this little rascal. I'd also like to send some "Good Thoughts" to Henry T. Brown. I bet he never imagined that the book he wrote in 1868 would still be finding new readers in 2013. I also bet that if he knew how I'd just downloaded his masterpiece over the Internet he would have been completely blown away. So, maybe we aren't in danger of losing the knowledge of the masters. Maybe we've reached the "cusp" where we can digitise all of this stuff and preserve it before it disappears into the mists of time. What do you think?