Elements of Style

Read the following two sentences and the second part of each of them looks like an afterthought or twist on the first part of it.  The compound sentences formed with conjunctions like "and" and "but" are sometimes vague in explaining the relationship. Such style of writing trigger the minds of the reader to recall something said earlier and form some relationship between the two parts.

"The early records of the city have disappeared, and the story of its first years can no longer be found."

"The situation is perilous, but there is still one chance of escape."


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The relationship between the two parts of the compound sentence can be made more clearer with better words like "as" or "although". This style helps the reader to keep his mind calm and relaxed.

"As the early records of the city have disappeared, the story of its first years can no longer be found."

"Although the situation is perilous, there is still one chance of escape."

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Using subordinate clauses and a complex statement is even better than any compound statement in terms of words it required or time it takes to parse it. The disadvantage of such compaction gives impression that it is too formally written.

"Owing to disappearance of the early records of the city, the story of its first years can no longer be found."

"In this perilous situation, there is still one chance of escape."


References:

Elements of Style