Now that Paul Ferraglio has finished with Plumier I think he would do us all a real service with a dissertation on this phenomenon! I have come across all conditions, from the venerable patina of age to the lump of corruption; at best a nuisance, at worst catastrophic. There seem to be three kinds. The mild, even, coating of "red rust" which can almost be wiped off; the generally clean (clean dirt, that is) surface with odd patches of rust here and there; and, worst of all, a coating of hard, blue-black deposit under which are cavernous pits. The first is little to worrry about, the second can be a problem, the third must be viewed with grave concern. Rust can form as a result of chemical action, electrolitic action, or both—one leading to the other. I think that in the case of "pitting rust" the chemical action in the pit generates quite heavy electrolytic action at the same site and each reinforces the other, so making bad worse. Whereas with the much more widespread but consequently more uniform coating the "currents" are more dispersed, and hence less active. However, the first thing is to get rid of the coating. There are chemical products available, notably KINGSTON Rust Remover, made by Sandersons, of Hull which I have used very successfully; but experience suggests that whilst such treatment is handy for removing rust from (e.g.) painting standards etc., it is not the best way for machined parts. I now use "wet or dry" abrasive paper, grade according to the delicacy of the work but usually not coarser than no. 220, WITH LASHINGS OF WATER. This may sound stupid, but (a) the action is far more effective (b) the rust disappears as sludge down the drain, not as dust all over the shop and, most important (c) any corrosive matter in the pits tends to be washed out. Rust is NOT infectious, but acids can and do form beneath it, and these do the damage. Once the surface rust has been removed if the pits are very mild I scrub with very hot water/stergene solution; if they are deep, I spot on Kingston rust remover with a brush and after the time allowed for action is over, scrub as before. IMMEDIATELY the scrubbing is over, the metal is dried and either given a spray with cellulose primer if the work is to be painted, or washed (or better, immersed) in Shell "ENSIS" oil grade 254. In fact, this oil is a moisture repellent, and articles can be dropped into it whilst wet; it is better to do this than to get a finger-mark on the metal whilst drying it! I mention cellulose primer; I use this because it can be applied very quickly, even if later work is to be done with oil-based enamel.

A special case arises with things like small cutters and tools. If no more than mild red-rusted, then the drill is:

1. put into a glass jar with Rest Remover agitating till the action has ceased (the tools will appear to be lead coated, and in fact they are)
2. wash in very hot water (just tip them into another jar full of water ) so that they air-dry at once when taken out.
3. rub with a rag soaked in Meths. to remove the lead deposit
4. immerse in nearly boiling water/stergene solution (very little of the latter)
5. tip out the solution, rinse with hot water, tip this out, and then tip (or place, if you prefer) the tools into a jar of Ensis 254. At no time are the tools touched by hand. They are now rust resistant for 6 months or more, or until you use them.

If heavily coated, then it is doubtful if they are worth bothering with, especially if pits have appeared at the cutting edge. In this case the rust remover is ineffective and the deposit must be removed by abrasion first. I simply rub them on wet-or-dry paper, under water; tack the sheet of No. 400 paper to a small board, make a block with little grooves in to take say 6 tools at a time, and rub them on the paper, turning over as needed. After which, start at (a) as described for the mild attack. Note: do not attempt to take off the rust either with ordinary emery cloth, or worse, with oil and a coarse oilstone. The trick is to use water all the way, which not only removes corrosion and the corrosive acids, but also avoids having the rust-remover inhibited by the presence of oil. The WORST thing to do is to squirt a dose of penetrating oil on a rusty surface before doing anything else!

The exception to this rule is the case of parts which may be more effectively handled in lathe or drilling machine—such as the shanks of ornamental drills, often—all too often—found rusted into their holes in the cabinet. In this case I use the same abrasive paper dry. Some ingenuity in making a holder for drills, if there are a lot to be treated, will be worthwhile. I have carefully checked and find that provided the instructions are followed i

Rust Remover doesn't harm the cutting edges. I have treated a hundred or more, using the drilling machine to rotate them, the chuck engaging with the enlarged part of the shank and the "blade" projecting into the space between jaws. A piece of linen tracing cloth used to avoid accidental damage to the cutter. The cutters were not touched by hand after spinning; release them from the chuck so that they fall into a box, and then tip (yes, again!) them all into the rust remover.

Oil is no help. If an article is oiled, and one small part either dries up or loses its coating, then rust will start there and will be more fierce than if the part were not oiled. Further, if the part is not to be used for long periods, the oil (normal oil,

that is) will degrade and form a varnish that is very difficult to remove. ENSIS will protect for 6 months or more, and can be renewed easily. If it has to be removed, then it washes off with petrol or benzene. For parts to be put away for a long time, use medicinal Vaseline, a real heavy coat, or pure lanoline BUT—don't get fingermarks on! The best drill is probably to use Ensis and then coat in Vaseline, but my own practice nowadays (I have the time, you see!) is to recoat- with Ensis at regular intervals.

The protective papers (V.P.I., which means Vapour Phase Inhibitor) are reasonably effective on articles stored in a closed compartment, and I have a piece in all drawers and cabinets. But I don't rely on it alone—it is there as an insurance in case I have missed giving any piece a proper treatment. I do use it instead of ordinary paper to wrap things up in, and here a word of warning. Not so long ago I prepared a job for painting, and,having degreased it, had to leave it, so wrapped it up in a piece of ordinary paper. 4 hours later it was covered in thin red rust. Verb Sap!

Parts which, like tailstock lock-screws and the like, have to be handled all the time, cannot conveniently be protected with oil. To overcome this my present practice is to give them a cosmetic treatment which also acts fairly well as a corrosion-resistant. That is, deliberately to form an oxide film which will prevent corrosive elements (your paws, for example) from getting at the metal. Simply done—just heat gently and evenly in a blowlamp or spirit lamp till it turns blue, and then quench in oil. To get a good colour, try to heat indirectly, as the colour will not form properly when the part is actually IN the flame. I do this now for all screwheads too, and any steel part of a similar nature which isn't hardened. It has the advantage that after a year or so it gives that patina of age which necessarily has been removed by the anti-rust treatment.

Members may feel a bit reluctant to apply the treatment I have mentioned to this part of the machine, for fear of upsetting the accuracy. This might be true for a SLIDE-lathe, but is not so important On a machine in which the sliding is all done on the rest. Further, I have found that one can get a deflection of between 5 and 10 thousandths of an inch between front and back shear of the bearers by doing no more than putting a thin wedge under one lathe foot; the bed is very weak in this respect, for all its weight. In fact, as I say, it doesn't matter very much. All the accurate work on the lathe is done close to the mandrel nose, and the slide-rest takes care of alignment. Long work is all done from the handrest, and bed alignment is then irrelevant. A rusty bed can, therefore, be treated exactly as I have described, (apart from tipping it into a jar, of course!) and provided the pits are all separated by reasonable areas of flat metal it will work perfectly well. If you want to "Renovate", then the only way of dealing with the pits is a 14" (or, better, and 18") file, followed by scraping to a flat plate. That, by the way, is the method used in nuking all the early "iron bearer" lathes; cold chisel, file, and then scraper. It is unlikely that any Holtz earlier than No. 1300 had a planed bed.

Those who can file flat and are prepared for a week or so of hard work will need no instruction from me; others are best advised not to attempt complete restoration. However, much can be done using "Wet and Dry", starting with No. 120 and working down to No. 320. The abrasive paper must be applied under a flat and heavy block, with an oval motion (long axis of the oval across the bed) the ovals overlapping well as you traverse along the bed. Once the worst of the discolouration is removed, then the surface can be refrosted with a scraper but wash it first to get corrosive products out of the pits. (NOTE, it is quite useless to try to scrape a bed unless the surface has first been "broken" with abrasive or file; cast iron takes up a glaze in service which will rapidly blunt a scraper.) This process will certainly improve the appearance of the bed, though it will not remove enough metal to get down to the bottom of any corrosion pits. No attempt should be made to do this, by the way, for if you treat any one part of the bed more than others it will come hollow.

The space between the bearers which guides the tongue of sliderest and tailstock is best treated similarly with abrasive but using no coarse grit. Tread carefully, and do not on any account check for tight spots on the tongues with the bed on its side; its own weight will close the gap. These guiding surfaces should be treated with the bed in its normal position and preferably assembled into the standards, for the effect of tightening the fixing bolts can introduce distortion. If you find tight and easy spots—slight differences are to be expected—check first that this is not the cause. Then ease the tight spots with a file taking care to keep it flat and square. Fine finish is not essential

here and draw-filing is sufficient. It may be necessary, if much has been taken off, later to adjust the tongue setting screws, or to solder on a thin piece of shim-brass to prevent rattle.

There are too many experts on this side in the Society for me to risk sticking my neck out, but for what it is worth my procedure is as follows. After removal of dust, any hard deposit, such as spilt varnish, congealed oil, etc., is very carefully removed with a cabinet scraper. This is not so difficult as it sounds as, in the case of machines (not only lathes) over 100 years old the vanish then used is pretty resistant to penetration by such dirt. So far as possible, all dirt is removed from the surface with a scrubbing brush and very mild detergent PROVIDED I am confident that the original varnish layer is intact. If not, then I go straight on with repeated doses of the following:

• Raw Linseed Oil, 4 parts.
• Pure Turpentine oil, 4 parts.
• Vinegar, 4 parts.
• Methylated Spirits, 1 part.

This is shaken up well and applied generously with a cloth. When dry, rubbed off with another cloth, and the process repeated. This is very effective in removing dirt, "feeding" the wood, and forming a base for any subsequent wax polish. The only reason for the prior scrubbing operation is economy—this stuff is just as good, but more expensive!

Any woodworm holes are treated with one of the commercial woodworm killers, applied with a disposable hypodermic syringe scrounged from the ward sister last time I was in hospital. Provided they have only been used for innocuous injections on one's own person, there is no risk of the lathe contracting any serious disorder. Any fractures in non loadbearing timber I try to repair by clueing, and I am old-fashioned enough to prefer animal or fish glues to modern synthetics; of the latter I restrict myself to Casco or Cascamite. Faults due to wear I leave alone, and I "undo" joints only when no alternative is possible—it is best to leave well alone. I have a few pieces of very old mahogany which I keep for repairs. Once all is clean I repeatedly wax with some soft furniture wax, suspected to be no more than beeswax and turps, and after a few months the wood is as good as new.

Whether to repaint or not must be carefully considered. If the machine is old it may well have been repainted several times—a fact readily ascertainable by examining parts "difficult to get at". If it has, I have no hesitation in repainting, but a machine over 100 years old, with the original paintwork, should only be repainted if it is so far gone as to be repulsive in appearance or liable to corrosion. If the paint is all there, but dull and rough, it can be treated to restore its surface. Wash all over with White Spirit to remove oil—you may have to use a brass scraper to get rid of clods of congealed oil but try to avoid scratching the paint itself. Difficult patches may need treatment with Benzene or Toluene, but if the oil has congealed to a varnish it will be insoluble and must be scraped off and then rubbed with No. 320 wet or dry with soapy water, lots of it. Then repolish that bit with the finest you can get—I use No. 600, again, lots of water. Once clean, the surface can be treated with a rubbing down material like "T-cut" (obtainable from the car shops) or even Brasso will do.

You will find that this will considerably improve the appearance provided the paint is sound. If it doesn't, then the paint itself has perished, and the only cure is a repaint. In fact, most of the early machines (pre-1900) were painted with a hard black japan and this stands up very well.

If a repaint Is to be done, then there are only two satisfactory finishes if the original appearance is to be restored. A first quality machinery enamel, (difficult to get in less than 1-gallon lots) or cellulose. (Both are modern paints, so the only alternative for the purist is to make up his own Japan as instructed in Holtzapffel!) I have used both, and now use cellulose on smaller parts, the machinery enamel on larger areas like iron legs etc. Whichever is used, it must be emphasized that the final appearance depends more on what is underneath the last coat than what that coat is made of, and for preparation work I always use cellulose—if only to save time. NOTE—it is QUITE useless doing a repaint with ANY of the "Do-it-yourself" household paints now sold. These are formulated, I think, for lack of drip from the brush, and have little or no merit otherwise.

First check that the old paint is sufficiently polymerized to withstand the cellulose solvents. This will be the case if the last repaint was more than 60 years ago. Just squirt or brush a little cellulose on a typical spot and see if it lifts the old paint. If it does, then all of this must be removed, using No. 80 wet-or-dry, with plenty of water. If not, then you need not be so vicious and a rub all over with No. 120 will serve. Take care to remove any rust, as detailed earlier, and keep all oil away. I use the little aerosol cans used for car touch-up and a typical lathe repaint will need two cans of primer (one red one grey) a tin of cellulose filler, and one or two cans of colour coat. It is handy to have some brushing "primer-filler" as well. Spray all over with red primer, two coats, (shake the tin well, and then shake it twice as long again) keeping the can at least a foot from the work, and spraying in bursts. Let this dry for an hour and then apply filler to all depressions with a knife. This filler will skin over in the tin if left open, and I put the lid on between each knife load. Put this stuff on in thin coats; this applies to all cellulose material, which dries by solvent evaporation. If it is thick the outer layer will dry, and prevent the solvent inside from escaping. Don't be too fussy about appearance, for 90% of the filler has to come off! Let it set for twice the time suggested on the tin, and then rub down with wetor-dry. For this work ask for "soft-back" paper; this moulds to the contours of the work better than the normal painters paper. If it is a large part, say an overhead standard, use No. 180, but otherwise No. 240 is coarse enough. Rub down till bare metal begins to appear, or the original paint starts to show through the red primer, ALL OVER. Dry the work and spray on a coat of red primer, then (when that is dry) grey primer. Now reexamine the work and fill any depressions that still appear with the filler; this time being more careful and fill only where necessary. Rub down again when set, with No. 320 this time, and stop when the red just shows under the grey, but making sure that you have brought the filler down level. You may get down to bare metal or old paint here and there—don't worrry; that shows you have done it properly!

Spray on another coat of red and then one of gray, as before, and then MOST CAREFULLY examine all over, filling any tiny spots that have appeared. You often find little pinholes in earlier filling at this stage. Rub this down very carefully indeed after it has set, using either the worn No. 320 or a finer grade still. Dry all over thoroughly (you must always do that, of course) and then spray on two more coats of primer in two colours as before. Leave these to set overnight. The final rubbing down should be done with No. 600 if you can get it, soft-back of course, aiming to get a fine surface all over, and stopping IMMEDIATELY the second colour shows through. When you have finished this process the job will be red with grey patches (or vice-versa) with NO traces of the gray filler showing anywhere. If it does, then you must cover the patch with a local spray of primer and rub that down again.

At this stage KEEP YOUR FINGERS OFF IT; handle only with a CLEAN cloth, and put the work down only on a clean sheet of paper. Let the surface set hard overnight and then prepare a stand on which to put the job when applying the colour. You may have to arrange a means of turning the job over, or round and round, to get at all parts—think it all out carefully, and have all ready. Shake up the can of colour for at least two minutes, and I find it pays to warm the can under the hot tap till it is at just under blood heat. Spray in short bursts keeping the spray at right-angles to the surface and about a foot away from the job. Don't try to get a heavy coat—you can put on a second and even a third at 10 minute intervals in a reasonably warm room. Once the work is black (or whatever colour) all over, leave it for an hour and then give another couple of coats at 10 minute intervals. Rub this down with No. 600, trying if possible to avoid going through to the primer; you want a matt surface all over, that's all. Use soapy water for this rub, but rinse afterwards. You can now give the final coats—two, at an interval of about 30 minutes. Let it dry for about an hour, and then put it in a warm, but not hot, place for at least 24 hours. I put mine on a shelf near a radiator and usually wait two days. You can now finish it; there are "rubbing down compounds" specially supplied to finish cellulose with, but I find these too fierce for machinery parts—fine on a large flat or curved surface, but take the corners off headstocks and things! So, use Brasso. Rub all over, gently with a soft cloth, as if polishing silver, but in STRAIGHT LINES, not round and round. Be careful at corners, even with brasso, or you may go through. The cloth will turn black—that is normal. The final result is almost undistinguishable from the original black japan as it WOULD have been 100 years ago, when new.

If you are using machinery enamel this is applied by brush after the last rubbing down of the primer. One coat is usually enough, though it is worth using two with a rub down between. Work freely and quickly, flowing the paint on and picking up any runs or drips. The art here is to use SLOW drying paint to give time to deal with these. Brushmarks usually run together in a few minutes. Don't expect to get good results with a cheap brush —my own Fez" brush cost £2—and "run in" a new brush on some unimportant piece of work first. There is no need to "cut" a brushed enamel—its natural finish is the best you will get. The main difference, of course, is that you should leave it long enough to dry, and during this time dust can be a pest. A large cardboard box to put over the work helps but make sure that its inside is not going to moult onto the paint. When I use enamel I usually leave it over the weekend to set before handling it, though it is normally touch dry in a few hours.

Now, I haven't mentioned two points. First, the use of "primer-filler". This is brushed on, and takes a couple of hours to set. It is useful in dealing with rough castings, or badly chipped paint, and much cheaper than aerosol primer. I usually give the job a spray with primer first, and then paint on the surfacer, leaving it about 3 hours before rubbing down. On very rough or cobbly areas a couple of coats can be given. It takes longer to set than spray, but may in fact save time in the end. The second point is the use of masking. The main snag here is that if you mask over with either masking tape or brown paper and paste, you may trap water underneath during the rubbing down process. So, for jobs—like a slidrest pedestal—with small areas that should be bare metal, it is best to let these be, and take the surplus paint off afterwards. I might put in a screw here and there to stop tapped holes from getting choked. On the headstock, however, I would mask up all machined surfaces, and take care to fill the oil holes etc. with something like "Blue-tale" or putty. This masking must be removed with great care, as there is a risk of peeling off the paint film with it. One thing, however, MUST be masked, and that is the rest of the workshop. If you don't, you may find the other parts of the machine—or other machines—spotted with spray-drift. I use a discarded sheet for this purpose.

There may be a few places where such elaborate procedures are not warranted. Either, some of the intermediate filling and rubbing down may be painted with primer-filler and then brush enamelled with no rubbing down. Such a case might be a lathe with iron standards as shown in Holtz, which would be prohibitive in cost to spray to start with, and in time to rub down afterwards, even if one could get the hand between the vertical members to do the job properly. So long as a slow-drying paint, which will give time to pick up runs, is used, a conventional "undercoat and two topcoats" treatment should be adequate.

An umbrella word to describe the surface decoration used by most O.T. Iathe builders on their machined metal surfaces. "Frosting"—the making of a pattern on a cast iron bed with a scraper—is one, and the curled patterns on brasswork another. Proper "frosting" needs considerable skill and patience to get an even pattern, but a pleasing substitute is not difficult. A very sharp 3-cornered scraper is needed, and it must be re-sharpened frequently. As mentioned already, you can't scrape a cast bed without first breaking the glaze; for this purpose it is necessary to rub over with No. 240 "wet-or-dry", (used wet) finishing with strokes parallel with the bed length. The surface will now be matt grey. Go down the length of the bed with the scraper, cuts at about 45° to the line of progress and about 1/2"—3/4" long. Repeat, a second line alongside, at the same angle, and so on till all the surface is covered. Now repeat, but at 45° the opposite way, over the top of the first set. Repeat again, but at about 30° this time, starting where the previous rows of scraper-marks overlap, and again repeat at the opposite angle. You now have four sets of superimposed scraper-marks and there should be no part where the original gray surface shows. On top of this, scrape rows of circular curls, overlapping circles about 3/8"—1/2~, diameter, made in a continuous stroke of the scraper, full length of the bed; and then a second set, the rows overlapping the first, and so on. (This sounds a lot, but is done quite rapidly, about 5 minutes a set for a Holtz bearer). Finish off with a repeat of the first pattern of 45° overlapping scrapes. Rub over with oil as soon as you have finished. (But get no oil on during the process). The result will be a very tolerable frosting, almost professional in appearance, and the same procedure can be used on any flat surface. I always frost (but very lightly) on all surfaces after I have bedded them in with the scraper. e.g. on sliderest vees etc., as this frosting helps to hold the oil.

Decoration on brasswork, especially chucks and so on, calls for more consideration. These are usually varnished or lacquered, and if a substantial part is still covered it is better to leave it alone, as it is difficult to find the typical 19th century yellowing lacquer these days. However, if it has badly discoloured, the lacquer is first removed by abrasion, and the surface then dressed with "polishing stick". These are sticks about 13/4~' X 3/16" x 12" long with various grades of emery PAPER (not cloth) glued round them. They are obtainable from Horological Materials stockists, but can readily be made up—the necessary paper can be obtained from the same sources. Grades 2, 1 and 0 will usually suffice—00 and 000 will polish rather than leave the fine graining needed. Experiment on a piece of brass first; I think you will find that grade 1 will leave the required grain, which should always lie along the longest line of the part. If the surface is very bad, then start with 2, then 1 across the line of the first, working till the scratches from the first are obliterated. If No. 1 doesn't give you a fine enough grain, cross the lines with No. 0 till those left by the No. 1 disappear. To make the "curlicues" simply draw them with the point of a piece of charcoal, or a charcoal artists pencil. (Which must BE charcoal, not wax impregnated in any way). The surface should then be lacquered or varnished, but it will not look yellow like the original—not with any lacquer I have found, anyway.

Some makers, Holtz among them, used what I can only call a "fern" decoration. Stripes across the work, with rays curving out from the stripes. This is done with the polishing stick. Grain with straight lines, first, then find a No. 1 polishing stick the corners of which are not worn. (The paper is glued on right round the stick, of course). Lay the stick narrow edge on the work, using the thickness of the stick as a gauge from the edge. Cock it over at a slight angle, make a forward stroke about 4" long and then sweep the stick over sideways in a curve, lifting the handle end slightly materials—brass slightly finer than steel, and larger parts coarser than small ones.

The cross-marks found on Holtz cutting-frame cutters are made in the same way, but without the sideways sweep. Though these are so regular I think he must have had a machine to make them with! Overlapping circular patterns, seldom found on O.T. lathes but not unattractive (found on watch-cases often enough) are made by fitting a piece of dowel in the drilling machine the end turned dead flat and square, impregnating this with fine emery powder, and bringing the dowel down onto the machined surface with firm but not too heavy pressure. A slow speed is best, and oil should be used. The problem here is to get the circles evenly spaced, and some form of guide and spacer is almost essential.

Finally, a word about machine buffing. A 6" buff at 3000 RPM using "red stuff" as a soap, will impart a high polish in seconds, compared with hours work with brasso. BUT, I would use it only on parts (on an old machine) which suffer constant handling. The treatment will take off all sharp edges, and the finish adopted by most of the lathe-makers was characterized by Braining and sharp corners rather than blended corners buffed to high polish.

A soft bronze or brass wire rotary brush in the drilling machine at 2450 rpm will clean up most brass and wrought-iron parts, and is excellent for getting Holtz deep threads clean—better than a steel brush, which is too fierce. Most of the parts will be wrought iron, not steel, and this is wrought iron, much softer than M.S. Steel wire brushes are only appropriate for removing heavy rust deposits, or clarted-up grease.

There is available a range of rubber-bound abrasives known as "BRIGHTBOY", to be had from E.H. Bernfield & Co., Ltd., 231 The Vale, London W3 7QS. These come in various grades, either as lumps like indiarubbers, wheels for grinding machines, or mounted points. The lumps are excellent for Braining and polishing and one can make curlicues with the mounted points, though not as elegant as the charcoal ones.

It often happens in repairs to lathes that one needs to carry between centres a part which has had one of the original centres turned off; in adapting a Tee-rest, for example, to fit another pedestal. A centre can be made by attaching a small piece of brass with araldite, cutting a centre in it, and then knocking off the brass afterwards. Araldite is a very useful adhesive and I have a geared cutting frame in which one of the teeth was stuck on "temporarily" with Araldite many years ago, and still is in service. Clinical cleanliness is essential to get good adhesion.

The removal of screws and bolts can be very difficult on old machines. Certain precautions are advisable. The large flat-headed screws in O.T. chucks are, I think, made of a high-carbon iron or steel. The trick of giving a sharp blow to the screwdriver can be fatal—they go brittle with age. Soak first in "Plus-gas Formula 'A'". Clean out the slot in the screw and file the screwdriver to a good fit. If the screw is tapped into brass, heat the latter till you can only just hold it; if into iron or steel, apply a hot rod or a soldering iron to the screw-head till the Plus-gas begins to smoke. Apply a torque as if TIGHTENING the screw and suddenly reverse the torque. If the screw gives ever so slightly in the tightening direction you are home and dry, and it should come out easily; if not, repeat the action. If it is really stubborn, then try to get the oil and heat at the other end of the screw, and give this end VERY LIGHT taps with a brass punch before attacking the business end with the screwdriver.

Screws with a normal head can be treated similarly, the fit of the screwdriver being most important, but here, when applying the TIGHTENING torque you can safely give the screwdriver a smart blow with a hammer. And again, if you wish, when untightening; it's only the flat-head screws that seem to be brittle.

Serious damage can be done in removing screws in the mahogany standards—those holding treadles etc. If these are rusted in you may well lap out the thread in the wood altogether. Don't use Plus-gas—it removes paint and varnish. Mix up 50 - 50 Oil of Wintergreen and Pink Paraffin, and apply this at both ends. Use a wire brush to remove all visible rust at both ends of the exposed screw. Give the oil plenty of time—a day or so if bad— to soak in and then screw the screw IN, not more than one turn. If it won't go, try heat on the head {not the point) of the screw till the oil begins to fume and try again. It may take A LONG TIME for the oil to work if it is badly rusted, and you might try drilling a small hole at a downward angle to meet the screw in mid length, and inject oil down there. However, screw IN one turn, and de-rust the newly exposed thread. Screw OUT two turns, and again de-rust the thread showing. Repeat this process, first one way, then the other, each time removing rust from the newly exposed thread. In this way you will reduce t e lapping action of the rust to a minimum.

These screws are usually carbon steel, hardened at the point; don't be tempted to try softening them and rehardening after reforming the point if your machine is numbered (Holtz) at less than 2000 or you will risk crystalline fractures. Better to get a local firm to grind them. Treadle cranks were usually wrought iron with carbon steel ends hammer welded on What appears to be a badly worn centre-hold is more often one filled with a cement of polymerized oil and metal/wood dust. A carbon steel twist drill or centre-drill will remove this, better than one of High-speed steel.

I have said nothing about repairs and renovations as this would take far too long. In any case, those competent to effect repairs will know as much about it as I do whilst others would be well advised to seek the help of these competent members! However, there are one or two points which are of some importance. These old machines— and the youngest may now be qualifying for the O.A.P.—are part of our industrial history and the older the more so. If they were buildings all would have a Preservation Order put on them by the Authorities This being so, it behaves us to take care that in repairing any machine we do not destroy important historical evidence. Repairs and replacements MUST be carried out, for it would be a crime for these machines to relapse into mere museum pieces, but I would plead that all such repairs be documented with a record of the original state and the work done, to be kept with the machine (and perhaps a copy with the Society?)

If alterations are made, then the greatest thought should be given before undertaking any work which is irreversible. This applies especially to unusual machines, or any other 100 years old. If a 22.18 tpi leadscrew end nut is replaced with one of 10 or 20 tpi for more effective use of the machine, well and good; this is as it should be. But, the original parts should be preserved, and the alteration carried out, if possible, so that the original parts could be replaced. Again, drawings and photographs should be made and kept with t e machines Some of the "mystery" parts which appear on machines today might well be very Important to us if the owner who fitted them t50 years ago had taken this precaution! I am, of course, referring to work on the basic machine, sliderest, etc. The normal practice of workers in O.T. of adding new attachments over the years—even over the centuries before long—is well understood, and no Industrial Archaeologist will make a mistake over them in the years to come. My own practice on old machinery (not only O.T. lathes, but engines and plant of all sorts) is to stamp or engrave my initials and date on any replacement or un-original part. No doubt these markings will be a puzzle to people 100 years from now as similar marking might be to us today, but at least I have tried!