You might remember these from your childhood, or this might be your first ever encounter with a Drinking Bird. Whether it’s nostalgia or new wonder, these birds are a fantastic blend of practical science and a cool toy to watch work. These “Dippy Birds” have been around for years, and you can’t fool us – you’ve always wanted one.
Why is this bird so interesting? Well it’s science in action, and they’ve been around for a very long time. Where did Drinking Birds come from? A Chinese drinking bird toy dating back to 1910s~1930s named insatiable birdie is described in Yakov Perelman’s Physics for Entertainment. The book explained the “insatiable” mechanism: “Since the head tube’s temperature becomes lower than that of the tail reservoir, this causes a drop in the pressure of the saturated vapours in the head-tube …” It was said in Shanghai, China, that when Albert Einstein and his wife, Elsa, arrived in Shanghai in 1922, they were fascinated by the Chinese “insatiable birdie” toy. The drinking bird was patented in the US by Miles V. Sullivan in 1946. He was a Ph.D. inventor-scientist at Bell Labs in Murray Hill, NJ, USA. they quickly became a hot souvenir and gift item.
Do you get the complex relationship between chemistry and physics that makes this simple heat engine operate? It really doesn’t matter, they’re just fun to watch, but we’re going to tell you anyway because it’s interesting.
THE SECOND LAW OF THERMODYNAMICS EMBODIED IN A GLASS BIRD
Is this a perpetual motion machine? Well, the answer is it’s more than that. Technically yes, but it’s not energy for free! Temperature differentials drive the bird to go up and down, but it can’t do so without temperature variation. This is why it’s not completely perpetual motion and is not that efficient, but it’s still very cool.? So if it’s not a kind of a perpetual motion machine what it is? It proves The Second Law of Thermodynamics which states (paraphrased): that energy can neither be created nor destroyed in a closed system. So how does that relate to our little glass birdie here?
The liquid in the bottom of the bird body is methylene chloride, which has a very low boiling point, and therefore evaporates quickly. At room temperature, one or two degrees temperature difference causes the bright red chemical to climb to the drinking birds head. Suddenly, top heavy, he falls over. The felt head, soaked in the water from the cup, cools the methylene chloride, and it drains back to the bottom of the bird again giving the illusion of him drinking. The bird rights itself, and it starts all over again.
How does the Drinking Bird work?
- You wet the drinking bird’s head
- Water evaporates from the drinking bird’s head
- This cools the drinking bird’s head
- Which causes the vapour in the drinking birds’ head to condense
- This results in a lower pressure in the drinking bird’s head
- Which sucks liquid up from the base of the drinking bird
- As liquid flows into the head, the drinking bird becomes top-heavy and tips forward
- When it tips over, the bottom end of the neck tube rises above the liquid in the bottom
- This causes vapour to rise up the tube to the head
- Which pushes liquid back down from the head to the bottom
- The increased weight of liquid in the bottom restores the drinking bird to an upright position
What physics does the Drinking Bird actually demonstrate then?
This one experiment manages to demonstrate a whole range of physical laws, including the combined gas law, the ideal gas law, the Maxwell-Boltzmann distribution, the heat of vaporisation, torque, centre of mass, capillary action, and probably a few others.
Here are some helpful tips for enjoying your drinking bird. It will also help if your customers have questions on it’s function:
Fairway’s Hints and Tips :
For the common “Classic” drinking bird, place a few large coins in a little pile between the bird’s legs. This will make it more stable and less likely to fall over and break.
The birds with red fluid inside are more traditional, but be warned that the red liquid does fade in sunlight. The blue liquid is less prone to fading. If the plastic legs are slightly bowed in or out after you purchase your bird, the “pivot” may stick slightly. This will make the bird stick a bit and it won’t swing back and forth as freely as it should. It is possible to bend the legs inwards or outwards slightly, but take care not to break them. The best technique is to squeeze them in or out and gently warm the plastic with a hair dryer. This will soften it slightly and help to make the adjustment permanent, but take care as too much heat will completely melt the plastic.
Remember, most of the “drinking birds” contain Methylene Chloride, also known as Dichloromethane. This just happens to be a chemical used in paint stripper! It will badly damage paintwork and most plastics. While drinking birds are great to watch, they’re not ideal for smaller children as toys. The glass on these birds is fragile. If your bird breaks it WILL damage furniture and wood flooring. There isn’t much that you can do except wipe it up as quick as possible with rubber gloves and don’t let pets or children anywhere near it.
The drinking bird isn’t drinking – it stays upright.
Have you fully wetted just the head part ? The rest of the bird must remain dry. Another thing to check is if the liquid rises in the tube. If not, the bird may have a broken seal or be defective. If it does rise up, then try gently wriggling the metal pivot slightly downwards towards the body, and test the bird again. If it swings towards the water and stays there, you have gone too far.
The drinking bird drinks really slow.
Drinking birds are not fast, but if it’s painstakingly slow, make sure that the head part is fully wet with water and that the rest of the body is completely dry. You can also try gently wriggling the metal pivot slightly downwards towards the body, and test the bird again. If it swings towards the water and stays there, you have gone too far.
The drinking bird hits its body on the glass I’m using.
Try to avoid using a glass which is narrower at the top than the bottom. If possible, use a glass which is wider at the top. Keep the bird as far away from the glass as possible, providing its beak does not interfere with the side of the glass. If this fails, gently bend the metal pivot so that the bird is very slightly further forwards towards the glass (when upright) as if by “pushing on the bird’s back”. Don’t slide the body up or down in the pivot. This should make the bird tend to lean forward further and swing back less.
The drinking bird tips into my glass of water and doesn’t come back up.
When the bird dips into the water, it should not go further than the main glass tube being horizontal (the tube must not be lower at the head end), otherwise the liquid can get “stuck” in the head bulb and prevent it from returning. If it does go further than horizontal:
(a) Bird dips beyond horizontal : Where the metal pivot meets the plastic legs, there is a small plastic lug or “stopper” moulded on to the legs, just on one side. This is designed to prevent the bird from dipping too deep. An enlarged portion of the flat part of the metal pivot is supposed to hit this plastic lug and prevent the bird leaning too far. Try gripping the flat part of the metal pivot (on the relevant side) firmly with pliers, then leaning the bird back slightly so that the metal pivot becomes very slightly twisted. This can do the trick. Note that the depth to which the bird “dips” should be limited by this stopper, not by it hitting the glass of water, as this can cause damage.
(b) Bird does not dip beyond horizontal : Try gently wriggling the metal pivot slightly upwards towards the head, and test it again.
The drinking bird stops drinking after a while.
Do you have enough water in your glass. Water evaporates out of the glass after a while. If the birds head doesn’t get wet, the drinking bird stops working. Is the head staying wet ? Ideally, the beak should just touch the surface of the water on each dip. If this is not right, try adjusting the water height. If the bird dips too deep, the head can get too wet, resulting in water running down to the body. This stops it working. If water persists in dripping down to the body, try drying the head off and start again.
Hand Boilers are looped and twisted glass sculptures containing a liquid that will “boil” as heat is transferred from your bare hand. Hand boilers demonstrate Charles’s Law and vapor-liquid equilibrium. The colored liquid in the boiler is comprised of a volatile mixture of liquids that have a boiling point just above room temperature. The body heat from your hand causes the liquid to boil, which in turn makes the liquid evaporate, turning it to gas. The expanding gas pushes the liquid upwards and when you release your hand, equilibrium is re-established. The gas condenses into a liquid again and flows back into the lower bulb. Simply hold the large bulb end in the palm of your hand and within minutes, your body heat will cause the liquid to rise. In popular culture, hand boilers used to be sometimes known as “love meters” because the tube that separates the upper and lower bulbs is twisted into a heart shape and the volatile liquid is colored red. Love meters were and still are a common collector’s item or a souvenir. Depending on how the item was packaged, one would grasp the lower bulb to “prove” how passionate one was, or a couple would each grasp one end to see who would force the liquid into the other’s bulb. Once out of your hands, it takes a few minutes for the liquid to cool down and return to the large bulb. Pretty fascinating science toy and an excellent demonstration of energy transfer. Comes in three different colors: blue, green and red. Hand boilers make great items to sell in your gift shop. They’re colourful and interesting. Hand boilers aren’t expensive for you, the wholesale buyer, or your customers. Kids are fascinated as much, if not more the adults when they see them in action. Remember these are not for young children. We recommend 8 and older to handle them as they are made of fragile glass and have a volatile mixture of liquids that places the boiling point of the mixture to just above room temperature. Hand boilers come in all kinds of shapes and names today.
With these products still on the market, why not add them to your collection of gifts you sell? They’ve still popular even today. We sell thousands of them every year. Sell them as a retro novelty gift or a science gift. You will be glad you purchased them to sell. It’s one item that won’t stay on the shelves long.
If you’re interested in selling these in your gift shop, give us a call at 1-800-325-0889. You can get pricing in our catalog. Note: We DO NOT sell by the piece. You will need to set up an account with us.
Please remember to tell your gift shop customers that this product is not a toy and is not intended for use by children under 8 years of age. It should be use under adult supervision. Avoid breaking glass, as the drinking bird contains methylene chloride and may stain clothing and other surfaces. Do not swallow or allow to come into contact with eyes. The liquid is flammable so keep away from flame and other heat sources. CHOKING HAZARD: Contains small parts. The drinking bird is not for children under 8 years of age.