Gearing up for a big hop
QUESTION Does a system equivalent to gears exist in nature?
There’s a single instance of a gear-like structure in nature — that of the juvenile planthopper nymph Issus coleoptratus.
In 2013, zoologists Malcolm Burrows and Gregory sutton at Cambridge University produced an electron micrograph that demonstrated the joints that connect the hind legs to the body of the nymph are rounded like a cog, with a series of tiny, intermeshing teeth.
Planthopper nymphs use these ‘gears’ for coordination. They can take off in just two milliseconds, reaching speeds of almost four metres per second.
Because their legs swing laterally, if one moved a fraction of a second earlier than the other, it would push the insect off course into an uncontrollable spin. The gears lock their back legs together, letting both extend in the same instant.
They function in the same ways as man-made gears. The ten to 12 tapered teeth have filleted curves at the base designed to reduce wear over time.
The planthopper nymph loses its ‘gears’ when it reaches adulthood.
scientists are not sure why this is, but one weakness in a gear system is that if a tooth is damaged, the effectiveness of the whole mechanism is compromised. While gear teeth in nymphs can be repaired in the next moult, when it sheds its skin in order to grow, any damage in adulthood remains permanent.
Dr Ian Smith, Cambridge.
QUESTION Where is the deepest water well in Britain?
WOODINGDEAN near Brighton is the deepest hand-dug water well in the world. excavated between 1858 and 1862, it extends to a depth of 1,285ft — that’s 35ft deeper than the empire state Building is high — with 850ft below sea level.
The well was part of a plan by the Brighton Board of Guardians to supply water to the Warren Farm Industrial school and a new workhouse at the top of what is now the elm Grove district. The aim of the school was to teach young reprobates ‘the habits of industry’ and relieve them from ‘the bane of pauperism’.
The plan was to sink a 6ft wide, bricklined shaft down 400ft to the subterranean water table.
Unfortunately, no water was found. Lateral shafts were dug to no avail, so the decision was taken to keep digging.
Work continued for four years, with men working 24 hours a day by candlelight in appalling conditions. One at a time within the confines of a 4ft circle, they would load buckets with spoil and line the shaft with bricks. Winchmen stood on tiny platforms cut into the side of the shaft, passing spoil up and bricks down.
On sunday, March 16, 1862, one of the well-diggers noticed the ground begin to swell — a sign they had finally reached the water table. By the time he vacated the shaft, which took 45 minutes, the crust had broken and the well flooded.
In 1878, the well was abandoned in favour of Brighton’s piped water supply. It is preserved outside the Nuffield hospital on Warren road, Woodingdean.
This was the site of the former Fitzherbert roman Catholic school, when the well was in the woodwork shed. There was a school rumour that there was a dead nun at the bottom of the well.
Nigel Percy, Hove, E. Sussex.
QUESTION How would 100 archers from Henry V’s army fare against 100 riflemen from Wellington’s army assuming, as in the Sharpe books, the riflemen fire three rounds a minute?
The scenario of the conflict would have a considerable bearing on the result.
Would they face each other in a field with 300 yards between them, or
Jumping start: A planthopper
would the battle occur in wooded terrain where both sides could take cover and use foraging tactics, carrying out ‘target of opportunity’ shooting?
A longbow with a 100lb pull fires arrows with tempered armour-piercing heads at a rate of ten per minute. A flintlock rifle uses black powder and a soft lead ball to fire three rounds per minute.
In a field, the archers would be positioned behind the infantry or cavalry and so prove to be difficult targets. Launching a continuous shower of 1,000 deadly arrows per minute, they would cause severe casualties to the riflemen.
The riflemen could increase their rate of fire by forming ranks three men deep, where the first man kneels to fire, the second man is ready to fire and the third man reloads.
This wall of lead would massacre the infantry and cavalry, but have minimal effect on the archers behind. Therefore, in this scenario, the odds are on the archers causing the most casualties to the riflemen.
If the archers stood on the flank of their formation without protection, the first volley from the riflemen would obliterate them.
The advantage of cover in a wood would be to the riflemen’s benefit. They fired from a prone or kneeling position, as this made it easier to steady the rifle for aim and offered the enemy a smaller target.
The faster rate of fire from the longbows would be no real advantage. The archer would have to make his shots while standing, exposing a larger target for the riflemen.
In the event of close-quarter fighting, a rifleman with a 14in bayonet on the end of his 48in rifle would be expected to have acquitted himself better than a sword-wielding bowman.
John Atkins, Greatstone-on-Sea, Kent.
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