# Semicolon usage

What is trying to be said in this sentence?

One profile reading shall be taken for every 200 square feet for the first 1,000 square feet; for each additional 500 square feet or less, one profile reading shall be taken.

• Your question in the body of your post doesn't quite match the title: what exactly do you want to know? – Dɑvïd Feb 6 '14 at 13:18
• Would this sentence cover anything less than 1000 square feet, based on current sentence structure? – Todd Feb 6 '14 at 13:26
• Yes - the first part (before semi-colon) covers 200 sq ft segments up to the first 1000 sq ft. – Dɑvïd Feb 6 '14 at 13:31
• If there were only 450 square feet, how many readings would be required? 2 or 3. – Todd Feb 6 '14 at 13:36

• Would you say this sentence covers readings less than 1000? Say 450 square feet and if so is it because of the phrasing in the second sentence? – Todd Feb 6 '14 at 13:21
• Of course I would say this sentence covers readings less than 1000. In fact I just did, four times over, in the first four lines of my answer. – RegDwigнt Feb 6 '14 at 13:24
• Thanks RegDwight. I was wondering if the number of readings would be 2 or 3 for the 450sqft based on sentence structure. – Todd Feb 6 '14 at 13:31
• @Todd: based on the sentence structure, I think its ambiguous. Do things under 200 sqft require any profile readings? – Peter Shor Feb 6 '14 at 14:10
• @PeterShor I think the answer has to be 3. Clearly if the square footage was 1001, it would require 6, from what we have been instructed. So if you would do a reading for a one square foot space, then you would presumably be expected to do one for fifty. – WS2 Feb 6 '14 at 14:32

The semicolon here is being used to separate two complete clauses; they could equally be divided into separate sentences. The original as quoted:

One profile reading shall be taken for every 200 square feet for the first 1,000 square feet; for each additional 500 square feet or less, one profile reading shall be taken.

is the same as:

One profile reading shall be taken for every 200 square feet for the first 1,000 square feet. For each additional 500 square feet or less, one profile reading shall be taken.

By using the semicolon, the writer in effect keeps the second set of "readings" close-joined to the first set. The instructions, as such, seem fairly clear.