@erikah!) called Emma Raducanu won the US Open and in doing so, propelled herself to number 1 seed in the British rankings and number 21 in the world.It brought tennis into the spotlight and no doubt encouraged many people both young and old to dust off their rackets and get down to the park to knock a few balls around. After all, tennis is possibly the most 'English' of sports and like many other 'English' sports, we're pretty rubbish at it.
As a kid, we'd use them to play cricket on the street with, to play football with when our footballs had burst and to generally throw around and practise our catching. We probably used tennis balls for everything other than playing tennis, and it got me thinking...
The first thing I need to point out is that we are talking here about Lawn Tennis as opposed to 'Real' Tennis which is a game that had been played since the middle ages and started in France. Lawn Tennis was developed by retired Army Major, Maj. Walter Clopton Wingfield who suddenly finding himself with no countries to fight with and colonise, decided to piss-off the French by stealing their sport and turning it into something much more English and politely competitive.
He created and copyrighted the rules in 1873 and the upper-classes loved it, so much so that the members of the All England Croquet Club, based in Wimbledon, decided to play Tennis on their Croquet lawns and such was its popularity that in 1874, they renamed themselves as the All England Croquet and Lawn Tennis Club. They refined the rules, published a rulebook and the rest is history.
Croquet? Another sport played on a lawn whose origins also lie in France in the Middle Ages and which we again, stole, brought back to England and improved before selling it around the world.
In the United States, a chemist and inventor, Charles Goodyear, had invented a process to make rubber, a substance that was easily degraded by heat, chemicals and wore out quickly and used since ancient times, into a hard-wearing, waterproof material whilst retaining it's 'boing' by removing the sulphur found in the rubber and then heating it up. He patented the process which is called vulcanisation in 1844 and its uses were limited only by one's imagination. One of the things that was imagined were balls, and it was a vulcanised rubber ball that the old Major used to whack back and forth with his friend, the equally plummy Major Harry Gem as they developed the new sport of lawn tennis. Previously, Real Tennis had used leather balls stuffed with hair and putty and were not noted for their bounciness!
The rubber balls had been imported from Germany where they had perfected a way of making balls with a shell of rubber, and filled with air.
There was another problem, however. The elasticity of the rubber meant that the ball could fly for miles at a high rate of knots and so a lawn tennis advocate, John Moyer Heathcote suggested covering the rubber with flannel to both slow it as it flew through the air due to the fluffy cloth creating drag (resistance to the air) and stopping it bouncing quite so high!
The original rubber balls from Germany had a shell formed by folding a cloverleaf shape up into a sphere, but this wasn't a very accurate representation of a sphere and there were seams that would easily split so these days, the balls are formed in two halves using a combination of natural and synthetic rubber and before being glued together.
Under pressure, heated air is injected into the ball as it's sealed before two lozenge-shaped pieces of 'felt', now made from wool or nylon are soaked in glue before being wrapped around the rubber shell. This is how the distinctive seams on a tennis ball are created. I always thought that was how the parts of the shell were joined! They are then rolled and steamed to create a perfect and smooth sphere and a perfect bond between the rubber and felt before being printed and packaged in a pressurized container.
Yes, to maintain consistency no matter at what altitude in the world you may be playing, the cans are pressurized, to around 14psi, the same as the balls themselves, for transport to keep them at the same firmness wherever you pop open the can! Where do you think Pringles got their idea from? In certain professional tournaments at high-altitude locations, balls are made with a lower internal air pressure to provide the players with the same 'bounce' and flight characteristics as they have at any other venue.
Cheaper practise balls generally have no internal pressurization.
The pressurized containers were invented by Pennsylvania Rubber Company, Penn, which today is one of the biggest manufacturers of tennis balls in the world.
Now we will have a look at the legal dimensions and specifications of a tennis ball as per the International Tennis Federation's rule book!
Size: Between 6.54 and 6.86 cm (2.57 and 2.70 inches).
Mass: Between 56.0 and 59.4 g (1.98 and 2.10 ounces).
Bounce: So how the bounce criteria is determined is by dropping the ball from a height of 254 cm (100 inches) onto concrete and it must bounce back to a height between 135 and 147 cm (53 and 58 inches).
The testing must take place at sea level and at 20 °C (68 °F) with a relative humidity of 60%!
The balls must be white or yellow...
So, with the advent of Colour TV in the 1960s and tennis becoming an extremely popular sport for watching at home, it was decided to change the colour of the ball from white, which was easy to see on a Black and White television but very difficult on a colour set, to yellow.
Yellow? Are you sure?
Absolutely. The official name of a tennis ball colour is 'Optic Yellow' but if you were to read through the whole ITF pdf, you'd notice that's as far as they specify. Now the problem arises that if it's converted to a Pantone reference and given a Hex key, the colour will be classed as either an official fluorescent or neon colour both of which are listed as a shade of green.
The debate over this has raged on for years on the internet and I was just interested to see what people think, hence the poll and hence why there was a divided opinion which backed up everything I'd read about. Personally, I say yellow, but I can certainly understand how some may say green.
The considered opinion from various sources on Google is that there are roughly 325million made each year. Many of the factories producing these are in Thailand and The Philippines as South East Asia is where the vast majority of the world's rubber is produced. The biggest names in the game are the likes of Penn, Wilson, Head, Dunlop and Slazenger.
Absolutely. The covering of the ball can be made from a number of materials including wool, cotton and nylon and is usually a secret combination by the manufacturer. Each covering will give the ball a slightly different flight characteristic as the drag will change depending on the tightness of the cloth's knit and how 'hairy' it is.
At Wimbledon, 53000 balls are used during the tournament. The balls have been supplied by Slazenger since 1902 and it is the longest-running sporting-goods partnership in sporting history.
Balls are changed after the first seven games and then after every nine games and used balls are sold daily for £2.50 per can of 3!
This is an excellent question as over 100million a year end up in the world's landfill sites and take around 450 years to break down. There is an excellent Non-profit organisation in the US called Recycle Balls who are placing bins near every tennis club to collect old balls which are ground up and will then be used for a multitude of projects including horse arenas and new tennis courts. Some balls which aren't ground up will be sold on to dog owners as dog balls!
If you want to see some creative and practical uses for old tennis balls, go here
There you go, a full post on the humble tennis ball but perhaps not so humble, for I'll leave you with a quote from the great American tennis player, Billie Jean King, who said...
"I love the smell of the ball and the sound of the ball hitting the strings. The seam on the ball reminds me of the separation between the land and the ocean on earth."
@nathen007