Обусловьте функцию for и but и переведите предложения на русский язык:1.

Определите функцию for и but и переведите предложения на российский язык:

1. For the best accuracy the carriage should be as light as possible.
2. Every designer should be responsible for the good and long service of his device.
3. The road must be laid out with a view to economy in original cost and maintenance, for generally its lifetime may be limited.
4. Everything was ready for the research to begin.
5. The train bound for the South was driven by a powerful locomotive.
6. A transformer is a device for raising or lowering voltage.
7. Nowadays there are means for transmitting energy over long distances.
8. For types of cable are provided for use with drilling machines.
9. But in a piece of timber, whether this be used for a table top or a beam, the radial and still more the tangential shrinkage is of the utmost importance.
10. Instruments based on this principle have been described, but the method now universally employed in accurate work is an electrical method.
11. Nothing but a double row of ball bearings can improve the machine.
12. But the table, though filled up, was to be extended by the addition of other elements unpredicted by Mendeleyev.