Many orchestrators still feel this information is relevant today, and if you do a Google search you will find sites that have recorded the samples and offer courses based around the original text. What’s valuable to us here is that one of the greatest orchestrators ever, and incidentally Stravinsky’s teacher, preserved his working knowledge and approach to the craft. Every serious orchestrator must read this book and should own a copy. The free IMSLP link contains texts in English, German, and the original Russian.