Having handled often lamps made by Willis & Bates, I am still surprised by the small diferences found on their lamps. How a small company can be great in variety - or how slow I am in noticing (all) the differences! The recent acquisition of the Vapalux 300 of 1943 vintage led me to look at the various big size (1¼") filler caps. And sure enough, there are differences that to me indicate a refinement of the product likely motivated by savings. None of this - in case of these caps - dramatic, mind, even if considering the oft mentioned production peak of 2000 lamps per week in the war years - which I highly doubt as fact anyway. But savings just the same, as less brass was needed to arrive at the same product. Shown above are - from left - a fuel cap of a E41 from 1941-ish, a cap from the said 300 with 1943 stamped into the ventilator, and a cap of a 1944 Vapalux 300. By the way, they show different finish as they were polished, left alone and sand-blasted respectively. "Inside" of these caps things look rather different, and it has all to do with the way the pressure relief screw is seated and its varying length. On the E41 cap it is the massive spigot-like protrusion in the cap that is constructional overkill, while having no added practical value at all. Soon this was remedied, showing the result as on the cap of the 1943 Vapalux where a shortened pressure relief screw is amply seated in a reduced centre of the cap. Finally on the Vapalux 300 from 1944, a means of securing this relief screw by a small brass split pen, the former appearing rather longer than needed; indeed, some shorter of such screws have been noticed. On the outside, a difference in diameter of these screws was noticed, another small saving of brass that must have been in high demand during this wartime period of producing the Vapalux 300. Again, diminishing this size did nothing detrimental to its functioning. This prompted me to compare other such screws, and I found the one on a Vapalux M1 of even smaller size, this time simply dictated by economy rather than scarcity. What in retrospect seems so obvious, it has taken some considerable time to arrive at a more economic product that was fully functional nevertheless. But same can be said of the model 320 lamp that I happen to find plain ugly - but is kept in my smallish collection as the last Bialaddin model with a new model tank just the same. Because as for looks, I love the bold statement in brass of those early big caps I liken to link with times when solid quality was a given in most products of that (pre-war) era.
As it was a relatively small company, their adherence to strict design parameters might not have been so high on their list... in the sense that different workers may have had 'their own way of doing things' and if it didn't compromise the functional quality, it made it out of the factory gates. They certainly weren't shy about mixing up parts from different models and using up old parts when necessary. It's just a theory really but it might explain what you find in the field.
All true @ColinG, but that relates more to how lamps were assembled with mixed parts. With these fuel caps I simply illustrate what was found on my lamps and how an initial design was pared down to meet likely stringent demands, never to be reversed. @JEFF JOHNSON The alloy caps were introduced when Aladdin Industries already were in control, evidently seeking further economy. For some reason this material was soon abandoned, perhaps because it was too weak on the threads, so appeared mainly, if not exclusively, on the maroon Bialaddin with a red top. When the civil green Bia's appeared in 1949, they all had brass fuel caps once more, but with the coarse serration - soon in two sizes 1¼ and 1" as on the 305 models - that was not long lived either and gone on the 310 model. Unless a works diary should turn up, by now not a likely event, we can only guess as to the why and, lesser so, the when of these detail changes. Till then, we can only share facts and sometimes ponder why they exist. Mike
