United States. War Department

“ We can here give only a very rough description of the sounds of Russian.
Hard and Soft Consonants. Most Russian consonants occur in two varieties: hard (or plain) and soft (or palatalized) .
In producing a hard consonant the Russian speaker lowers the middle or back of his tongue and slightly thrusts out his lips. This gives the consonant a dull sound; to the English speaker's ear the Russian hard consonant often sounds as if it had a short glide like a w after it. ”

“ Before a hard consonant the distinction of hard and soft consonants is maintained: [banka] банка "can, container" has hard [n] , but [vanjka] ванька "Johnnie" has soft [nj] .
Long Consonants. In English we have long consonants only in phrases and compounds, such as ten nights, pen-knife; in Russian there are long consonants in all kinds of positions: [vanna] ванна "bathtub," [žžeč] сжечь "to burn up," [ silka] ссылка "exile," [s soljyu] с солью "with salt." Note that the consonants [šč, žj] are always long. ”