Category: Blog

The early design history of the fountain pen is full of outstanding examples of innovation. Sometimes one glance is enough to tell you that you have found one of these gems. The Swan 4500 is unquestionably one.

In the early days of fountain pens, it was assumed that—with the exception of a few special-purpose users—most nibs would be flexible. And one issue faced by engineers was how to ensure a continuous flow of ink, no matter wide the tines were flexed apart.

This model, from the earliest days of the 20^th century, boasts what we now refer to as an “over-and-under” feed. The designer’s intention was that the lower feed would provide a flow of ink, and an exchange of air to equalize pressure in the barrel reservoir. The upper feed would both wick ink to the very end of the nib, and limit the amount of flex to something reasonable. An adjustable button housed in the main feed would also provide the user with a means of custom ink flow regulation.

Another outstanding—if short-lived—innovation was a filling system which would spare users the necessity of unscrewing the section each time the pen needed ink.

i. features

The upper feed is quite robust, and for good reason: it’s made of the same 14kt gold as the nib itself. In the usual run of over-and-under feeds are made of hard rubber. While it is an excellent material, it is not at it’s best when it is very thin, as it tends to be brittle. But using gold for a thin over-feed overcomes this problem, and actually reinforces the nib’s natural springiness.

In examining the over-feed alone, we can see a few important details, unique to these Mabie-Todd pens. The exposed length of the feed is u-shaped in cross-section. This serves to prevent permanent bending under flexion. Additionally, there is a bend at the mid-point, opposing the upward flex of the nib. This again reinforces the nib in use, and keeps the feed in place.

When properly assembled, this feed is placed so that the end is very close to the tip. This holds a supply of ink at the ready, no matter how much is needed for the width of line.

The lower feed is also quite different from those we usually see. Made of hard rubber, it is shaped at both ends, and is pierced though it’s entire length. Most unusually, it is vented at the midpoint, allowing for huge ink flow. Two air channels run along the bottom length, allowing for extra pressure equalization as necessary.

The diamond-shaped longitudinal hole is designed to house another unique feature: a sterling silver wire feed extender, fit into a hard rubber button which rests against the lower side of the under-feed. This feed-extender helps to wick ink down from the end of the barrel, again in an attempt to help the ink flow keep up with the demands of the nib at full flexion.

Because the wires are in constant contact with the sides of the barrel, the extender may also have been planned to act like the early Parker “Lucky Curve”, helping ink in the feed to wick back down into the barrel when upright. This would have helped reduce the common eyedropper-related problem of a very messy nib and feed when not in use.

This brings us to the truly unique feature of this pen. The small “bulb”—attached to the wire feed extender, nestled snugly below the main feed—is also part of the filling system. The button can be caught with a thumbnail and pulled upward, out of the feed, exposing the wires. (See the diagram at the top of the page for a fabulous illustration of this.) Now the reason for the huge hole through the main feed becomes evident: a fine eyedropper can then fill the reservoir (in this case, the barrel) with ink directly through the feed. When full, the button is firmly pushed back home, like a cork in a bottle.

Additionally, as advertised, the bulb can be adjusted in place. This, in theory, enables the user to regulate the flow of ink to match their hand.

External-filling eyedropper pens are very rare, never having become very popular. This certainly did mean that delicate Victorian ladies didn’t have to wrestle with tight threading on their pens (or wait for their mighty husbands to return home, for much-needed assistance.) And it may have reduced some wear-and-tear on delicate threads. And the idea of regulating the ink flow may have appealed to the artistic writer; unfortunately the regulation process would have to be undergone whenever the pen was filled, and the button was displaced. Also, inky fingers were still pretty much guaranteed, which may have been the last straw for what ended up being a gimmick (although a great one, as gimmicks go).

The nib, typical of early Mabie-Todd production, is fabulous. When this nib was made, the days of fanciful Victorian handwriting were not long ago. This particular example is marked as a “broad point”; what we now refer to as a “stub”, measuring in at about 1.0 mm. It is also designated as a number “3”, an indication of the diameter of the nib’s size; specifically as it relates to it’s inside curve.

It’s flexibility is astounding. Springy, yet responsive, it can safely flex to about double it’s original line width. (Keep in mind that, even when expertly and deliberately made to be flexible, it’s only safe to flex any nib to about 70% capacity. Any more and you are inviting permanent damage. If you see it on the internet, don’t assume you can do it at home!)

The only real shortcoming of this nib is a fairly minor one: there is no stress-relief hole at the end of the slit. Often referred to by neophytes as a “breather” hole, the stress-relief hole serves an important function. Gold, like any alloy containing copper, gets brittle the more it moves. And all of the energy of tine flexion ends up compressing the little spot at the base of the slit. This is not a huge problem when a nib is properly engineered, like this one. But having one there is good insurance. However, there are plenty of nibs, like this one, which have no hole, are a hundred years old, and have lots of life in them yet. So we will let the lack of a stress-relief hole go this time.

ii. disassembly

Disassembly is a fairly straightforward process. Remember a couple of basic, very important, principles and you won’t go wrong: patience, and heat.

Heat is the enemy of plastic, but the best friend of hard rubber. Hard rubber can withstand much more heat than plastics—easily as high as 200º f—before softening, and it retains it’s form, requiring active shaping to deform. As well, at a certain magical point (around that 200º f point), it will actually pop back into it’s original shape. It’s like an instant reset button, and this quality has saved many a repair person.

It may be tempting to use hot water, but do not, under any circumstances! Water, and especially hot water, will quickly and permanently discolour hard rubber. So stick to dry heat only.

As with all eyedropper pens, the gripping section is often screwed down quite tightly. (As an aside, Waterman actually marketed a special wrench to tighten and loosen sections on their eyedropper pens!) If it is stubborn, simply apply heat until warm to the touch, then try again. A non-slip pad can help grip things a little more firmly.

Once the section is threaded off the barrel, take a good look up the back end of the section. If it is filled with crusted ink residue, then the feed may be stuck in place with dried ink. In that case, more patience is warranted, and a very, very brief soak (less than five minutes) in cool ammonia water can help to cut through the residue. Be aware that this may well affect the colour of the section, so try everything else (dry heat) first. If you have an ultrasonic cleaner, this is very effective in reducing bath time and in loosening hard-to-reach spaces.

The wire feed extender comes out first, through the back end. The tiny button beneath the under-feed can be gently pushed against to encourage this. The wire is fairly soft sterling silver, so try hard not to bend it. There may be varying amounts of corrosion you can’t see, and bends and breaks always happen there first. That would be bad, so be careful and patient. (We may have mentioned that last before.) When you see the way it fits, it is obvious why the hole through the main feed is diamond-shaped in cross-section.

It is a good idea to make a mark to designate the alignment of the nib/feeds assembly in the section. The section actually moulds to the shape of the assembly, and you will want to align it the same way when re-assembling the pen. Some people put a discrete notch at the back of the threads, which is hidden when the section is in place. Others might put a dot of colour. Temporary is better than permanent, always. And photographing things as you go is always a good idea, as you never know when you might need a reference.

Once the extender is out, the next step is to work out the gold nib and over-feed, through the front. It is safest to work these out as a unit, although it is not crucial to keep them together (the over-feed is much shorter than the nib, and will come out completely first). The important thing here is not to bend the over-feed, but to go patiently and carefully. Heat the section up before you begin, and gently rotate the nib around the central axis of the length of the pen, while pulling gently. The nib is actually tapered gently, with the thickest part at the tip, so it will become looser the further out it comes.

Next, and last, is the main feed. With the nib out, this should be fairly loose in the section, and it should pull right out, from whichever end is convenient.

iii. cleaning

The best time to clean a pen thoroughly is when it is apart. The gold and silver can be soaked in ammonia water, scrubbed with a soft toothbrush, and rinsed in plain water. The wire of the feed extender can be cleaned with a piece of the very finest steel wool, but be careful to get every tiny bit of steel residue cleaned off when you are done (wee bits floating around in a filled pen is bad). Try to get all of the old ink residue off, as some old inks can be corrosive. Silver is robust, but is much more prone to corrosion than gold. An excellent tool for cleaning and polishing the gold parts is a jeweller’s cloth impregnated with rouge.

The main feed can be soaked in ammonia, and also scrubbed with a toothbrush. Try to get any dried ink out of it’s nooks and crannies; clean holes and channels means good ink flow. Again, flush with plain water and pat it dry.

The section and barrel can be flushed with cool water. A large syringe or baster is an excellent tool for this. You can clean out the inside with damp cotton swabs, but be sure not to leave any fluffy bits inside (remember: wee bits + floating = bad?) This may take a lot of swabs! It’s a good idea to give inside the cap the same treatment.

iv. re-assembly

Re-assembly is the reverse of dis-assembly. Easy to say, I know. Keep in mind some tips:

• The main feed will be a bit loose, until everything is in place. Be sure it stays aligned with the mark you made on the section, and check it often during the re-assembly process. It wants to rotate in place.
• Always use dry heat to prepare the section when fitting the nib and over-feed, so as to avoid stressing the material.
• Use our reference photos when positioning the nib in the section, and between the feeds. The over-feed should be almost at the tip of the nib. (Note that the main feed in our photo is not yet fully seated in the section. However, it’s position relative to the nib is as it should be.)



• Remember that the nib/feeds assembly will be a bit loose until the section has cooled down. You may be tempted to push the nib in further than it needs to go, but wait until things are cool to judge this one. However, as evidenced by the advert illustration, the nib is designed to sit further down the section than is seen in many modern pens.
• Use the magical nature of hard rubber to your advantage. Once everything is back together, use dry heat to warm the entire section with nib, feeds, and extender in place. Take it up to the point where the smell of rubber is quite obvious, and it is very warm to touch. This will allow the material to even out it’s stresses and conform to the various necessary shapes. If something has become deformed, it will pop back into shape. Just don’t try this on non-hard-rubber plastics!

v. write!

An eyedropper pen is almost always an excellent writer; their shortcomings mostly involved the inherent messiness of carrying them around. This pen is no exception, and even after a century is still a better writer than most. Remember, though: don’t over-flex the nib! If you want massive line-variation, get a brush.

Another good practice with eyedropper pens is to always keep them topped up with ink. If you let one get much below half-full, you may end up with flow problems, and more of a mess than usual in the cap.

The Swan 4500 is one of the most outstanding eyedropper pens made. It’s engineering is unrivaled for it’s time, and has the added benefit of a most triumphant appearance. It’s flexibility and responsiveness is considered by many to be unparalleled. If you keep it clean, and away from excess water & sunlight, you will have a pen that will impress your own descendants, probably well into the next century.

P.S.: I know, the cap on ours is missing a piece at the lip. You can’t have everything…