Ken M. Harrison's latest book is a complete guide for amateur astronomers who want to obtain detailed narrowband images of the Sun using a digital spectroheliograph (SHG). The SHG allows the safe imaging of the Sun without the expense of commercial ‘etalon’ solar filters. As the supporting software continues to be refined, the use of the digital spectroheliograph will become more and more mainstream and has the potential to replace the expensive solar filters currently in use. The early ch...

Astronomical Spectroscopy for Amateurs is a complete guide for amateur astronomers who are looking for a new challenge. After a brief overview of the development of spectroscopes and an introduction to the theory of stellar spectra, the book goes on to examine the various types of spectroscopes available to amateurs. Next, practical sections address all aspects of setting-up and using various types of commercially-available and home-built spectroscopes. A final part gives detailed instruct...

Grating Spectroscopes and How to Use Them is written for amateur astronomers who are just getting into this field of astronomy. Transmission grating spectroscopes look like simple filters and are designed to screw into place on the eyepiece of a telescope for visual use, or into the camera adapter for digicam or CCD imaging. Using the most popular commercially made filter gratings – Rainbow Optics (US) and Star Analyzer (UK) – as examples, this book provides the reader with information on ...

Refreshed with a new design, Oxford Practice Grammar is a three-level English grammar practice series for the classroom or self-study. Its tried and trusted methodology provides clear explanations and lots of extra practice. Oxford Practice Grammar knows that students need different types of explanation and practice at each stage of their study. Basic provides lots of practice and short explanations; Intermediate gives you more detail with extended practice; Advanced gives challenging prac...

Packed with clear guidance on the nuts and bolts of grammar and plenty of examples, this text will help students master the fundamentals of English grammar and tackle written assignments with confidence.60+ bite-sized units help students overcome common areas of difficulty, such as forming different tenses, using connectives to link ideas and build an argument, punctuating sentences and choosing the right words.Each unit is presented on a double-page spread, making it easy ...

The blueprint for becoming the man you were made to be—in marriage, family, work, friendships, with God in all of life.“If you want a no-nonsense guide to getting manhood right, this is it.”—Evander Holyfield, four-time world heavyweight championGuys often approach life like it’s a pickup football game. They make up the rules as they go. They are sloppy rather than disciplined. Many lose interest and simply watch from the sidelines. Yet a m...

Read by the author.Are you ready to stop wasting time and start turning your mundane life into one of adventure and blessing? Ken Harrison, Chairman and CEO of Promise Keepers, masterfully weaves together powerful stories and deep truths from Scripture to point you to the life for which God has called you.Ask Christians what they expect to happen to them after they die, and most will say they will go to heaven. And they’ll probably say that...

The blueprint for becoming the man you were made to be—in marriage, family, work, friendships, with God in all of life.“If you want a no-nonsense guide to getting manhood right, this is it.”—Evander Holyfield, four-time world heavyweight championGuys often approach life like it’s a pickup football game. They make up the rules as they go. They are sloppy rather than disciplined. Many lose interest and simply watch from the sidelines. Yet a m...

Are you ready to stop wasting time and start turning your mundane life into one of adventure and blessing? Ken Harrison, Chairman and CEO of Promise Keepers, masterfully weaves together powerful stories and deep truths from Scripture to point you to the life for which God has called you.Ask Christians what they expect to happen to them after they die, and most will say they will go to heaven. And they’ll probably say that they will meet Jesus and hope to hear Him s...

Decades of research have produced profound insights into how student learning and motivation can be unleashed—and it's not through technology or even the best of lectures. In Super Courses, education expert and bestselling author Ken Bain tells the fascinating story of enterprising college, graduate school, and high school teachers who are using evidence-based approaches to spark deeper levels of learning, critical thinking, and creativity—whether teaching online, in class, or in ...

From "an important writer in every sense" (David Foster Wallace), a novel that imagines a future in which sweeping civil conflict has forced America's young people to flee its borders, into an unwelcoming world.One such American is Ron Patterson, who finds himself on distant shores, working as a repairman and sharing a room with other refugees. In an unnamed city wedged between ocean and lush mountainous forest, Ron can almost imagine a stable life for himself. Esp...

More than 25 of the greatest Science Fiction stories ever written—many in eBook form for the very first time. More than four hundred pages of top flight fiction selected by the editors at www.fantasticstoriesoftheimagination.com, including 'Ticking' by Allen M. Steele; 'All Cats are Gray' by Andre Norton; 'The Velvet Glove' by Harry Harrison; 'The Day of the Boomer Dukes' by Frederic Pohl; 'The Troubadour' by Peter Sherman; 'Riya's Foundling' by Algis Budrys; 'Asleep in the Forest of the T...