The Roundness Problem: A Property the Catalogue Has Avoided Long Enough

A Property That Keeps Arriving Uninvited

I have been at the offices for seventeen years. In that time, I have reviewed entries involving mass, span, displacement, and depth. I have catalogued objects measured in tonnes, in metres, in board-feet, and, on one occasion I prefer not to revisit, in fluid ounces. What I have not done, and what the catalogue has conspicuously not done, is address roundness as a structural property in its own right. This week, the entries forced the matter.

Consider what arrived: a Peach, a Volkswagen Beetle, a Brioche Bun, a Croissant, a Bowling Pin, a Matryoshka Doll, a Porsche 911, and an Airbus Beluga. These are not eight unrelated objects. They are, with varying degrees of commitment, eight objects whose thicccness is delivered primarily through curvature. The catalogue has been accepting entries of this type for years without naming the property they hold in common. I am naming it now. Per Style Guide section II.3, a property must be identified before it can be evaluated. We are seventeen years late.

What Roundness Is Not

Roundness is not softness. I make this point because the week's entries invite a confusion that I find professionally irritating. A peach is soft. A Volkswagen Beetle is not. A brioche bun yields under pressure. A bowling pin, which weighs 1.53 kilograms and is constructed from hard maple or polyester composite, does not. The property they share is not tactile. It is geometric. Each of these objects achieves its girth by distributing mass outward from a central axis in a manner that produces, at minimum, one cross-section that is substantially circular.

Roundness is also not sphericality. A Matryoshka doll is not a sphere. Neither is a Porsche 911, which is round in the sense that its body panels refuse to commit to a flat surface anywhere along their length, producing a silhouette that reads as continuous and swelled rather than angular. A bowling pin is round in the middle and tapered at both ends. This is a specific and underappreciated form of roundness. I am calling it medial girth for the purposes of this report. The catalogue has no term for it. It should.

The Airbus Beluga and the Outer Limit

The Airbus Beluga is where the roundness argument becomes, if one will permit the word, serious. The Beluga's fuselage measures 7.4 metres in internal width at its widest cross-section. The aircraft was designed specifically to transport Airbus wing sections between manufacturing facilities, which is to say that its roundness is not incidental to its function. The roundness is the function. A flatter fuselage would not accommodate the cargo. The cargo required a fuselage of this diameter, and so a fuselage of this diameter was built. This is roundness as engineering necessity, which is the highest classification the property can achieve.

The Volkswagen Beetle presents a different case. The original Type 1, produced from 1938 through 2003 in its classic form, was not round because its engineering demanded roundness. It was round because Ferdinand Porsche and Erwin Komenda arrived at a shape that aerodynamic and manufacturing constraints, combined with the requirement for a rear-mounted air-cooled engine, produced organically. The roundness was the result, not the intention. The car is 1,539 millimetres tall and 1,539 millimetres wide at its widest point. I find this symmetry suspicious and have made a note. Roundness by necessity and roundness by result are both legitimate. The catalogue should say so, and does not.

On the Peach, Briefly, and Under Protest

I am aware that the peach is a fruit. I catalogued it under protest. I filed the objection with the records desk on Thursday morning, addressed to Margie, marked as formal. She has not responded. This is consistent with her pattern when she believes I am being obstinate, which is her word, not mine.

That said: a ripe Elberta peach measures approximately 7.6 centimetres in diameter and achieves its form through cellular expansion that the tree does not control with any precision. The peach is round because roundness is the path of least resistance for a drupe expanding under its own internal pressure. This is, structurally, the same argument as the Beluga. I do not enjoy saying this. The peach is in the catalogue. It meets the criterion. I have updated the card in the credenza accordingly, without enthusiasm. The amendment I intend to file with the records desk, two pages, addressed to Margie and copied to Teddy, will note the peach as the founding case. Teddy will attempt to make a counter-argument involving the Saturn V. The Saturn V is cylindrical. I have been very clear about this distinction since 2019 and I will be clear about it again.