So is an electrotransparent glass roof that allows passengers to control the amount of sunlight entering the cabin during the day, or, at night, to adjust the ambient lighting.

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One of the most arduous undertakings was to raise the roof 20 inches a seemingly small amount, but enough to dramatically open up the view of the water from a long upstairs balcony.

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"If we can secure this final amount then work can start on the roof in two months, " he said.

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There are sensors all around, in the nearby water and on the roof, that collect scientific data such as the amount of dissolved carbon dioxide in the bay.

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Earlier this year, a small amount of lead was taken from the church roof on two separate occasions, with larger amounts of lead flashing being removed overnight in two recent incidents, on 13 and 14 June.

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The danger was compounded by an overhead power cable, which broke loose and fell on the roof of the rear car, causing further arcing and a large amount of smoke inside the train.

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Or doubling the amount of energy produced from renewable sources, such as expensive, roof-top solar panels.

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No amount of argument will change the law of gravity as I slip off of a roof.

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