Original Newton's Cradle

An LB Classic! Designed by Mr Loncraine and Mr Broxton over 25 years ago! The first and still the best.

This demonstrates Newton's principle that 'action and reaction are equal and opposite'. If one of the steel balls is lifted and allowed to fall back at one end, then one will swing out the same distance at the other end. This causes the beginning of perpetual motion which dies down only as a result of friction, an interesting process to watch.

If you raise and release one ball, one ball is ejected the other side; if 2, then 2 balls are ejected. If you raise the single ball higher so it hits at a higher velocity, still only one ball is ejected. How does the system 'know' how many balls to eject?

According to our supplier (when pressed for instructions):

In order to adjust the ball swing of the Newton’s Cradle you use the screw driver provided to tighten or loosen screws located with in the small holes along the top of the main metal bars. This will shorten or lengthen the strings causing the swing of the balls to change. It is up to personal preference as to how the strings are adjusted.

We disagree:

Most people want the balls to swing for as long as possible; there's not really much 'personal preference' about it. You need to line the balls up both horizontally and vertically. Turn the screwdriver clockwise to lengthen the string on that side - the ball will move down and away from that side. So first, adjust the balls so that they line up when seen from above. Then either lower yourself down or raise the cradle up to eye level so you can see along the line of balls, and notice if any are too high or too low. If so, then lengthen/shorten strings equally per ball, as necessary to raise or lower them.

Dear Lagoon Group - I don't think that was at all 'obvious', and you really ought to include some instructions.

Measures 11.5 x 9.5 x 14 cm.