The manufacture of iodine by distillation of seaweed, established a few years ago in the isle of Tyree and other parts of the West Highlands, still goes on, and as is stated, with tenfold increase. The selling price, which used to be 1s. 3d. per ounce, is now not more than 5¾d.
In America it has been discovered that the canker-worm, which infests fruit-trees to a mischievous extent, can be effectually checked and destroyed by smearing the stem and branches with printers' ink. It is interesting to know that there are two ways in which printers' ink can be made use of for the suppression of pests. And in France experience has proved that the _Phylloxera_ can be destroyed by planting red maize between the rows of vines. The insects quit the vines and attack the maize-roots.
Meteorologists are well aware of the fact, that as a rule the barometer rises and falls twice within the twenty-four hours. Wherever observations are made, this movement is seen; and attempts have been made to refer it to the influence of tides in the air. But what causes the aërial tides? Some observers say magnetism, others say heat and differences of temperature. Mr Blanford, meteorological reporter to the government of India, has studied the subject; and in a communication to the Asiatic Society of Bengal, he remarks: 'It appears in a high degree probable that a great part of the diurnal irregularity of the barometric tides is due to the transfer of air from land to sea, and _vice versâ_, and to a similar transfer which may be proved to take place between the plains and the mountains. But the phenomenon is very complex, and much study and labour are yet required to unravel its elements, consisting as they do partly of elastic and reactionary pressure, partly of dynamic pressure, and partly of variations in the static pressure of the atmosphere. Till this shall have been done, and it shall be found, after all, that heat and its effects are insufficient to explain the phenomenon, it seems premature to resort to magnetic and electrical phenomena for the explanation of the barometric tides.'
Amateur meteorologists would do well to remember that the trustworthiness of the anemometer as a measurer of the force of the wind is seriously affected by the presence of trees; even a single tree will exert a disturbing influence. For wind-observations, the more open the space the better. We hear that the Meteorological Office is about to place at a high elevation an anemometer which will indicate its work to the observer below by telegraph. In the study of the weather, it would often be of advantage to know the rate and force of the wind on the top of St Paul's or Ben Lomond.