Good Questions: Starting right at the bottom

WE RETURN after the seasonal disruptions to answer readers' queries concerning matters meteorological, kinetic, fiscal and, to begin with, rectal.

Whose was the original bum immortalised in the remark: 'It's a bummer'? (Brian W Aldiss, Oxford).

This is a complex matter and we must be careful not to confuse the English 'bum' - meaning buttocks - with the American 'bum' - a drunkard, vagrant or worthless fellow. The latter derives from the German, bummler (a loafer or habitually tardy fellow), which in turn comes from the verb bummeln - to waste time or go slowly.

The English 'bum', far from being a contraction of buttocks as some have suggested, is a word of far older pedigree, dating back to at least 1530 ('I woold thy mother had kyst thy bum' is the oldest quotation given in the OED) and even spotted, in the form 'bom', in 1387. One of its earliest respectable uses was in the term 'bum-bailiff', an official who would make an arrest for debt by touching the debtor on the back. The word 'buttock' only made its first appearance with its present meaning in the 18th century.

The word 'bummer' itself has had several meanings in English. As long ago as 1675, it was used as a colloquial term for a bum-bailiff. Later meanings include 'a small truck with two low wheels and a log pole used for moving logs' (from a 1905 dictionary of forestry and logging terms), and 'that which hums or buzzes' (as in a 19th century Scottish proverb: 'The loudest bummer's no the best bee').

Meanwhile, back in America, bum was being used as an derogatory adjective in the middle of the 19th century, with a bum steer and a bum rap the earliest common expressions. The phrase 'it's a bummer' first appeared in the drug culture of the 1960s from 'bum trip' meaning an unpleasant or unsatisfactory drug experience.

As with the phrase 'bum's rush', whereby a person is propelled through a door by his collar and trouser-seat, the derivation is undoubtedly from the American bum (a tramp). So the questioner should have asked not whose bum, but which bum was the first bummer.

Sources: OED, Brewer's, Oxford Dictionary of Modern Slang.

Is it ever too cold to snow? If so, at what temperature does this happen? (J McCormack, Widnes).

Under normal conditions, it is unlikely to snow if the temperature is much more than two degrees above or below zero. But under certain circumstances, it can snow when it is much colder, and that is when British Rail may, quite legitimately, refer to 'the wrong type of snow'.

In general, snow is an aggregation of ice crystals which are formed in the atmosphere at temperatures far below freezing point. Near freezing point, crystals cling together and form snowflakes. (According to a recently accepted international classification system, incidentally, there are seven types of snow crystals: plates, stellars, columns, needles, spatial dendrites, capped columns and irregular.)

In the simplest terms, very cold temperatures in this country occur with clear skies in winter. With no cloud, there can be no snow. This is because cooler air holds less moisture, and no moisture means no snow.

In general, the higher you go, the colder it gets, but when the surface is colder than the air immediately above it, the inversion can lead to freezing rain - what starts as snow high in the atmosphere turns to rain on its way down, then freezes again on the ground.

The right conditions for snow are generally a near-zero temperature on the ground and moisture in the atmosphere. If it is too cold, however, there will be insufficient moisture. This is not always the case, however, particularly on the east coast of Britain, where a blast of cold air from central Europe can bring with it very dry snow - the wrong type of snow in BR terms.

Normal, reliable, British snow can be dispersed with salt (lowering its freezing point), but the colder, powdery snow from the east is liable to turn into an ice hazard if the same methods are applied.

Main source: Meteorological Office.

When the front car of a stationary queue of traffic begins to move forwards, why does the whole queue not move at the same time? Why does it take time for the movement to be transmitted down the queue? (Andrew Belsey, Cardiff).

This seems quite obvious when you consider the desire of each driver to leave a safe distance between himself and the chap in front in case sudden braking is necessary. But the question becomes more interesting when we bring lobsters into it.

Research on the spiny lobster (palinurus argus) has identified a habit of these creatures to migrate by walking along the sea bed in orderly tail-to-antenna queues. Experiments have shown that such lobster queues serve to reduce water resistance. In the laboratory, it has been shown that lobster queues can travel at 35cm per second, whereas the top speed of a lone lobster is only around 28cm per second.

This does, however, raise the question of how any lobster can join a lobster queue, since once the queue has got up speed another can never catch it, unless new recruits are swept up and joined to the front of the queue, which seems unlikely.

Perhaps if the bumpers of cars had devices attached to them which automatically clamped onto the car in front at traffic lights, lobster-like car queues could move off simultaneously when the lights turned green. There could also be benefits with reduction in drag, but there could be considerable hazards when the lights changed again.

It is easy to visualise 'turning on a sixpence', and to appreciate 'a penny for your thoughts' and even 'ten a penny' but what is so superior about ninepence that eightpence or sevenpence do not have, in the saying 'as nice as ninepence' or 'as right as ninepence'? (John Walker, Salisbury).

According to B A Phythian's Concise Dictionary of Phrase and Fable, the expression 'as neat as ninepence' owes 'more to alliteration than good sense'. Another old expression 'as fine as fippence' seems to be equivalent, even if nominally four pence less.

Brewer maintains that 'nice as ninepence' is a corruption of the phrase 'nice as nine-pins' and refers to the skittles' being set 'in three rows with the utmost exactitude or niceness'.

Silver ninepences, which were in common circulation until 1696, when all unmilled coin was called in to counter the growing crime of coin-clipping, were very pliable and were often given, bent, as love tokens. 'Nimble as ninepence' was a common phrase alluding to their pliability.

Also worth nine pence in the 17th century was the Irish shilling, which probably had no connection with the West Country phrase 'ninepence to the shilling', meaning deficient in intelligence, or thick as two short planks, but that's another story.

(Photograph omitted)