Your child is going to laugh. Let them.
Then tell them a bucket of molasses weighs about half again what a bucket of water weighs, and ask them to imagine a wave of it above their head. That is the trapdoor this book walks a reader through, and it is why I would put it in front of a nine year old ahead of almost anything else in the series.
Carmen and her father came from Italy to Boston four years ago and live in the North End, in the shadow of a big steel tank that has always leaked. In January 1919 the tank comes apart and empties into the streets, and Carmen is in them. Text adapted by Georgia Ball, art by Karen De La Vega, with a nonfiction section and photographs at the back.
The science it actually teaches
This is the best physics book on our Stealth Science shelf and I do not think it is close. Nothing else we carry gets a child to care about density, viscosity and pressure inside one afternoon, and the reason it works is that the whole event is absurd until you do the physics, at which point it stops being absurd and starts being obvious.
Density first. Molasses is heavier than water for the same amount of space, roughly half again as heavy. That single fact is most of the story. Fill a street with a metre of water and you have a bad flood. Fill it with a metre of molasses and you have half again the mass moving at you, and the push a moving fluid gives is set by how much mass is behind it. Buildings came off their footings. Steel bent. The same depth of water would have soaked the neighborhood and drained away.
Viscosity second, and this is the one your child has felt without naming. Viscosity is how much a fluid fights being made to flow. Water has almost none. Honey has a lot. You can swim in water because you can push against it and it gets out of your way and then closes behind you. You cannot do that in something thick. It does not let you push, and it does not let go. People in the North End were not drowning the way you drown in a river. They were held. That is why the rescue took so long and why so many of the injuries were crush injuries.
And it does not go anywhere afterward. Water leaves. Molasses sits in cellars and gutters and sets, and the cleanup went on for a very long time.
Third, temperature, which is the hinge of the whole event. Viscosity in something like this changes enormously with heat. Cold molasses barely moves. Warm it and it runs. That fact is doing two jobs at once in this story: it is why a tank that had been sitting through a New England winter behaved differently on a mild day, and it is why what came out moved far faster than anyone watching would have predicted from something that thick.
Fourth, and this is the part I would keep for the end, pressure. The pressure inside a tank of liquid is not the same everywhere. It goes up with depth and it goes up with density, which means the lowest seams of a tall tank full of a heavy liquid are carrying the worst of it. That is where tanks fail. This one had leaked from the day it was filled, and it had been painted brown, which is a detail worth sitting with, because brown paint on a brown liquid does not stop a leak. It stops you noticing one.
That is the whole chain and a nine year old can hold all four links: heavy, thick, warm, and a weak place at the bottom.
The child it lands with
The child who asks why. Not the child who likes disasters, the other one, who wants to know how a thing worked and gets annoyed when the answer is that it was very big and very sad.
This one also does well for a reader who has decided that history is boring, because it is a true event that sounds invented. There is no way to be bored by a tank of syrup taking down an elevated railway, and by the time they have stopped being amazed they have learned four properties of fluids.
And for a family where somebody came from somewhere: Carmen and her father are recent immigrants, still working out how America fits, and that is on the page as ordinary life rather than as a lesson.
One place to stop and talk
This is the one book on the shelf where I would stop and go to the kitchen, because the science is on a shelf in your house right now.
Get two identical cups. Fill one with water and one with syrup or honey, and weigh them. The heavier one is the density lesson, done, no explanation required. Then take a baking sheet, prop one end on a book, and pour a spoonful of each down it and count out loud. That gap is viscosity.
Then put the syrup in the fridge for an hour and pour it down the same slope again while your child counts. When it takes four times as long they will understand, in their hands, the thing that made a January morning in Boston behave the way it did.
Total cost: a cup of syrup. Total time: about ten minutes, plus the hour of waiting, which you can spend reading the rest of the book.
What to know going in
Twenty one people were killed and something over a hundred were hurt, along with horses. They did not go quickly. Being caught in something that thick means being held down and unable to breathe while people can see you and cannot reach you, and the book is written for grades 2 to 5, so it does not put that in front of your child in those words. You now know it and your child probably will not, and that is a fair trade at this age as long as nobody in the house is treating the whole thing as a comedy.
The company that owned the tank blamed the explosion on a bomb rather than on its own construction, and the fight over who was responsible ran for years. Your child does not need the legal history. They do need to know that somebody knew that tank leaked and painted it instead of fixing it.
On the page there is real peril and there is loss. It is still, of the disaster titles on our shelf, the one least likely to sit on a child at bedtime, because it is a hundred years old, it is nobody's grandmother, and it is over.
Where to get it
I Survived the Great Molasses Flood, 1919 is $12.99, and it is the one I would start with.
Start here for two reasons. It is the only one where your child arrives with no feelings about the event, so the science gets a clear run at them. And it is the one you can hand over and walk away from, which means you can be doing something else while your child works out what viscosity means.
If your child liked this one
Books we have written about that sit close to this one, by reading level and by subject.
California Wildfires, 2018 in Panels: How Fire Moves
I Survived the California Wildfires, 2018 (I Survived Graphic Novel #13) by Lauren Tarshis
Grade 2 to 5
Hurricane Katrina, 2005: Why They Could Not Leave
I Survived Hurricane Katrina, 2005 (I Survived Graphic Novel #6) by Lauren Tarshis
Grade 2 to 5
Attack of the Grizzlies, 1967: Who Fed the Bears
I Survived the Attack of the Grizzlies, 1967 (I Survived #17) by Lauren Tarshis
Grade 2 to 5
California Wildfires, 2018: A Fire Starts Years Early
I Survived the California Wildfires, 2018 (I Survived #20) by Lauren Tarshis
Grade 2 to 5
Browse every book we have written about by age, by kind of book and by subject: Find the right book for your child. Or see the whole Stealth Science shelf.
