Various bits'n'pieces help give a pen its appearance, in addition to the general styling, and they add up to a view of the general age of the pen. So here are the main components.
The Assortment of Clips
These are self-explanatory on the whole. They are very approximately the same scale, except the end view pictures of jewels. There are minor variations in appearance. The only one I found of specific technical interest - some early clips of the numbered pens have smaller neater lettering (right-hand specimen) and these are usually fixed by a rivet rather than the later screwed jewel.
the "Big Red"
Two clips from large and presumably expensive 30's pens; the left hand one a lever-filler and the right a vacuum-filler
Burnham used a consolingly small number of types of lever, in two basic sizes. What appear to be the earliest levers have no imprint. Then later levers were lollipop type and had the BP logo, followed by levers with the gothic B motif, and finally by plain levers. The gothic B levers in the larger size had a single or double circle surrounding the B. and a double circle is usually pre-war while the single circle is usually post-war. A sunburst motif appears on some post- war levers and probably the lever is generic and bought in. The plain levers start off at 21.5mm. long, then 20.5 mm. and 18.5mm levers appear. The shortest are probably the latest.
The later small levers were a curious example of useless Conway Stewart mimicry. The Conway original has a curve on the lever edge by the lollipop to catch on the barrel and stop the lever moving when not wanted. It also has tabs to engage the pressure bar. The Burnham lever has no tabs, but it does appear to have the curved edge.....but they never made the lever engage the plastic of the barrel of the pens!
Burnham lever without tabs (upper), Conway with tabs.
© Alan Charlton 2011
Burnham Nibs (1)
1 - 9 various 14 ct nibs carrying Burnham imprint; 10 - 11 Pelham and Chatsworth nibs with cursive imprints, presumably Burnham;
12 Caws nib, presumably Burnham
5 6 7 8
9 10 11 12
Burnham Nibs (2)
13 Warranted nib from Burnham "Big Red" perhaps a replacement; 14 Warranted nib from very early Burnham; 15 - 16 Warranted nibs from Burnhams, possibly original;
17 - 21 various plated Burnham nibs
22 "Music" nib in interchangeable mount for B48 or acrylic pen, a customisation?; 23 Glass nib from a B48; 24 Stainless tubular nib of A45
13 14 15 16
17 18 19 20
21 22 23 24
Interchangeable Nibs (1)
Section and nib of late acrylic pen (left) and an earlier B48.
Two different ordinary nibs for B48, fine and broad, with an Osmiroid Italic and an Esterbrook 2234 with the same fitting.
Interchangeable nib units for B48
3 different Italic nibs and a Manifold
Interchangeable nib units for late period acrylic pens, one with ladder feed in hard rubber, the other with injection-moulded acrylic feed. Both have plated italic nibs.
Interchangeable Nibs (2)
Box of B48 nib units
Interchangeable nib units for No. 47 pens
Interchangeable nib/section/sac units for No. 44 pens
There are only a few materials which make up the barrel and cap, the main visible parts of pens. The earliest material was vulcanite, better known in pens as hard rubber, followed by celluloid (nitrocellulose) and then very closely by casein. Only the last pens were made entirely of acrylic material.
The appearance of hard rubber is not very easy to vary, and it was common to use physically chased patterns to liven up the appearance of plain black hard rubber. Alternatively the rubber could be a mix of the few possible colours, commonly red and black. The black was basically coloured by carbon and the red possibly iron oxide.
Celluloid is easily produced in plain colours and organic dyes colour the mix. Simple variegated versions simply used more than one coloured component in the mix and the different components could be cut or broken into chips before they were combined – fused with the aid of a solvent and heat. More complicated patterns, such as cross-hatched patterns and Parker’s striped effect, used more than one step of fusing different coloured materials and then cutting up the fused mix and re- fusing it. Burnham did not go for the more elaborate versions much, only marbled (variegated) forms were common, usually with the different colours outlined in black, presumably with another dyed celluloid component. Very rarely a cross-hatched version has been found which presumably demanded a few cycles of combination, cutting, and re- fusing.
Casein was made from granular stock which was dyed, soaked and if desired mixed in desired combinations. It was then extruded as rod or sheet. The sheet was cut into rod before pen manufacture. The extruder nozzle was heated and this seems to have given a discoloured top and bottom surface to the sheet version, often recognisable as a two-stripe effect on the pen. Extrusion might be by pressure alone or by a screw mechanism and these produced differerent effects. Some items were made in “nearly plain” casein and this probably was made by deliberate incomplete mixing of dyeing material. Casein is sensitive to changes in humidity – why it was not a success in the USA with its range of climates. It helps to use an inner cap of hard rubber to protect a casein cap from the humidity of the ink, but Burnham never bothered with this refinement so their casein pens often have some distortion of the cap. And the surface of cap and barrel often shows crazing resulting from changes in humidity.
The acrylic material of the very last pens was all in solid plain colours and doesn’t merit a picture. Acrylic had been used for sections and the retaining jewels for cowled clips previously, and there was an inconspicuous moulding flash on these. The pen caps and barrels were better and lacked the flash. Many of the acrylic pens had a hard rubber comb feed, but a moulded acrylic feed also appeared.
Two versions of chased hard rubber, and two-colour red/black.
Left to right: straight seam celluloid, and 3 versions of spiral seam, the rightmost a cross-hatch pattern that hides the spiral effect.
Casein formed from a mixture of pellets of different colours, usually two. Mostly there is an additional veined effect in which might have been obtained by adding a third more liquid matrix. The top 4 are postwar, the bottom 4 are earlier, say 1939 to the end of the “The Burnham”era. These early versions tend to have more “metallic” lustre.
Examples of casein made with a spiral screw extruder: there is a repeating pattern of varying degree of subtlety, depending on the degree of mixing of the casein.
Flame patten casein - made with spiral screw extrusion: there is a repeating pattern but it is very evident because the casein components have been left as unmixed as possible
Examples of two-stripe casein. The third down suggests that this could perhaps be combined with the regularity of screw extrusion.
A very peculiar casein! Probably there is a matrix material, clear in one and blue in the other. A second opaque silver-grey layer is added which has been physically slit and stretched to open the slits.
If it was green this would be called “celery”, like some American celluloid pens. But this is casein as well as not being green..... Presumably, like the celluloid equivalent, it is made by repeated folding of thin material before it is cured.
Burnham had a problem with celluloid barrel ends, particularly in later years. Casein rod allowed barrel ends to be turned, but celluloid tube did not. So they put an elegant plastic end piece on the later celluloid torpedo-shaped pens (but the colours were often not very permanent). They avoided the problem to a large extent with earlier pens as so many were button-fillers, but some celluloid pens have a flat end-piece cemented on.
© Copyright Alan Charlton 2011