Henrietta spent years measuring star positions and sizes from photographs taken by the telescope at the Harvard College Observatory, where she worked. After Henrietta observed that certain stars had a fixed pattern to their changes, her discovery made it possible for astronomers to measure greater and greater distances—leading to our present understanding of the vast size of the universe.An astronomer of her time called Henrietta Leavitt “one of the most important women ever to touch astronomy,” and another close associate said she had the “best mind at the Harvard Observatory.” Henrietta Leaveitt's story will inspire young women and aspiring scientists of all kinds and includes additional information about the solar system and astronomy.

    As an adult, she dives even deeper. Whether she's designing submersibles, swimming with the whales, or taking deep-water walks, Sylvia Earle has dedicated her life to learning more about what she calls "the blue heart of the planet." With stunningly detailed pictures of the wonders of the sea, Life in the Ocean tells the story of Sylvia's growing passion and how her ocean exploration and advocacy have made her known around the world. This picture book biography also includes an informative author's note that will motivate young environmentalists.Life in the Ocean is one of The Washington Post's Best Kids Books of 2012

    It was the first trip across an engineering marvel that had taken nearly fourteen years to construct. The woman's husband was the chief engineer, and he knew all about the dangerous new technique involved. The woman insisted she learn as well. When he fell ill mid-construction, her knowledge came in handy. She supervised every aspect of the project while he was bedridden, and she continued to learn about things only men were supposed to know:math,science,engineering.Women weren't supposed to be engineers. But this woman insisted she could do it all, and her hard work helped to create one of the most iconic landmarks in the world. This is the story of Emily Roebling, the secret engineer behind the Brooklyn Bridge, from author-illustrator Rachel Dougherty.

    purple mountains’ majesty, mauvelous, jungle green, razzmatazz… What child doesn't love to hold a crayon in their hands?  But children didn't always have such magical boxes of crayons. Here’s the true story of an inventor who so loved nature’s vibrant colors that he found a way to bring the outside world to children – in a box for only a nickel!

    Birds leave, flowers, too. Apples and temperatures fall—then snow! Part poem, part silent stage, this luminous picture book puts autumn on display and captures the spirit of change that stays with us long after fall leaves. Unlock the secrets of this busy and beautiful time of year as the natural world makes way for winter.

    Wrote The Sand Reckoner and Got Killed Being Rude, ante meridiem (a.m.), Donner and Blitz in German, One Million, Euclid Wrote The Elements, Squares, Pacific and Atlantic Oceans, Whales Are Not Fish, The “There Are Zero . . .” Game, Sets, the Popularity of Zero, Why Boats Are Cheaper to Rent in the Winter, Triangles, Herbivores and Carnivores, the Colors of the Rainbow, a King in Checkmate, the Story of the Titanic, ≠ (not equal), x + 4 = 7, One Thousand, Counting by Hundreds, Reading 3:05 on a Clock, Rectangles.

    When Owen was stranded after the Dec 2004 tsunami, villagers in Kenya worked tirelessly to rescue him. Then, to everyone's amazement, the orphan hippo and the elderly tortoise adopted each other. Now they are inseparable, swimming, eating, and playing together. Adorable photos e-mailed from friend to friend quickly made them worldwide celebrities. Here is a joyous reminder that in times of trouble, friendship is stronger than the differences that too often pull us apart.

    Look at all the bricks!Grab a hard hat and all your tools, and get ready for a construction adventure in counting! This clever, rhyming picture book leads readers through a day in the life of a construction crew building with bricks. A brick may seem like just a simple block, but in groupings of ten, twenty, and more, it can create many impressive structures, from hotels to schools to skyscrapers. This is a terrific introduction to counting in quantities for children.A Christy Ottaviano Book

    His popular TV series brought whales, otters, and dolphins right into people s living rooms. Now, in this exciting picturebook biography, Dan Yaccarino introduces young readers to the man behind the snorkel. From the first moment he got a glimpse of what lived under the ocean s waves, Cousteau was hooked. And so he set sail aboard the Calypso to see the sea. He and his team of scientists invented diving equipment and waterproof cameras. They made films and televisions shows and wrote books so they could share what they learned. The oceans were a vast unexplored world, and Cousteau became our guide. And when he saw that pollution was taking its toll on the seas, Cousteau became our guide in how to protect the oceans as well."

    In this playful introduction to maps and geography, step by simple step, a young girl shows readers herself on a map of her room, her room on the map of her house, her house on the map of her street--all the way to her country on a map of the world. Once the reader is familiar with the maps, she demonstrates how readers can find their own country, state, and town--all the way back to their room--on each colorful map. Easy-to-read text, bright artwork, and charming details give children a lot to search for and will have them eager to help navigate on the next family vacation.  From the Hardcover Library Binding edition.

    Volume Two dramatizes the lives of Omar Khayyam, Albert Einstein, Ada Lovelace, and others.

    This celebration of the wonder and variety of earth's animals is "joyous...a book to be shared" (Booklist, starred review).

    Here is the incredible story of Elizabeth, a real-life elephant seal who made her home in the Avon River in the city of Christchurch, New Zealand. When Elizabeth decides to stretch out across a two-lane road, the citizens worry she might get hurt or cause traffic accidents, so a group of volunteers tows her out to sea. But Elizabeth swims all the way back to Christchurch. The volunteers catch her again and again—each time towing her farther, even hundreds of miles away—but, still, Elizabeth finds her way back home. Includes back matter with information about elephant seals.From the Hardcover edition.

    But Evelyn crawled in dirt and collected glow worms in jars. When girls grew up they were expected to marry and look after children. But Evelyn took charge of the London Zoo insect house, filling it with crawling and fluttering specimens and breathing life back into the dusty exhibits. In the early 1920s, women were expected to stay home, but Evelyn embarked on eight solo expeditions to distant islands. She collected over 70,000 insect specimens, discovered new species, had tangles with sticky spider webs, and tumbled from a cliff. Inspire children to believe in their dreams and blaze their own trail with the story of Evelyn's amazing life!

    By the time he was a teenager, he had made a vow: Someday I will turn the power of Niagara Falls into electricity. Here is the story of the ambitious young man who brought life-changing ideas to America, despite the obstructive efforts of his hero-turned-rival, Thomas Edison. From using alternating current to light up the Chicago World’s Fair to harnessing Niagara to electrify New York City and beyond, Nikola Tesla was a revolutionary ahead of his time. Remote controls, fluorescent lights, X-rays, speedometers, cell phones, even the radio — all resulted from Nikola Tesla’s inventions. Established biographer Elizabeth Rusch sheds light on this extraordinary figure, while fine artist Oliver Dominguez brings his life and inventions to vivid color.