and the charged press, which causes the ram to rise till there is a pressure of forty tons, whereupon the safety-valve of the large pump opens, and is kept so by a spring.  While this operation is going on, the attendant is occupied with filling the second press; which completed, he opens the communication between the large pump and the second press, taking care first to replace the safety-valve.  The ram of this press is then raised to the same height as the other, after which the safety-valve rises a second time.  The attendant, as he closes the valve which opens the communication between the large pump and the press, at the same time opens the valve between the small pumps and the presses; and the pressure, amounting to about 300 tons, exerted by the small pump, is allowed to remain on the rams for about seven minutes.  From which it appears that, allowing three minutes for emptying and charging the press, the process of expressing the oil takes only three minutes in all; and it is done by this press in this brief time in the most effectual manner.  The oil, as it is expressed, passes through the canvas and hair bags to a cistern, known as the spill-tank, which is just large enough to contain the produce of one day’s working.  The presses are worked by oil instead of water, as it keeps both presses and pumps in better order.  Each of them will produce 36 cwts. of cake per day of eleven hours, while the yield of oil is about 14 cwts.  The oil is pumped from the spill-tanks to larger ones, capable of holding from 25 to 100 tons, where it remains for some time in order to settle previously to being brought to the market.

I do not intend to enter into the relative merits of the various presses, but content myself with having explained to you the manner in which the oil is produced.

Before concluding, it may be interesting to give you some idea of the vast extent of this manufacture.  It appears, according to the official returns, that in the year 1841 we imported 364,000 quarters of seed.

THE OIL FROM LINSEED.

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| 1842 | 368,000 | 1847 | 439,000 | 1852 |   800,000 |
| 1843 | 470,000 | 1848 | 799,000 | 1853 | 1,000,000 |
| 1844 | 616,000 | 1849 | 626,000 | 1854 |   828,000 |
| 1845 | 666,000 | 1850 | 668,000 | 1855 |   757,000 |
| 1846 | 506,000 | 1851 | 630,000 | 1856 | 1,100,000 |
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Now if we take the last year’s imports, we shall find that the produce would amount to about 144,000 tons’ weight of oil-cake, and above 56,000 tons of oil.

The cake is used for feeding cattle, and the oil for burning, lubricating, painting, &c.; and a very large quantity is exported.

We find that to crush the seed imported in 1856 it required from 150 to 160 double hydraulic presses, nearly 100 of which were in Hull.  This shows the extent of our commerce in the seed of flax, to say nothing of its fibre; and is one more instance of the great results which may be wrought out of little things.  What a beautiful illustration of the bounty of Providence; and what an encouragement to the ingenuity of man!  Who knows what treasures may yet lie hidden in neglected fields, or to what untold wealth the human family may one day fall heir?