SCIENTIFIC PURSUITS AT HOME
greatest obstacle to it, and will cause objections. Dr. Roberg, who in everything that is minute and subtile is himself subtile, is best able to judge respecting it: if you would therefore be kind enough to leave this with him, I should like to hear his opinion. If Professor Valerius would lay aside his own and his father's Cartesianism, his opinion would also be valuable to me. I have materials enough on this subject to fill a large book, as is done by the learned with their speculations abroad; but as we have no appliances here for such large publications, I must cut my coat according to the cloth and introduce only the most general views. The use of this seems to me to enable us to investigate more thoroughly the nature of air and water in all its parts: for if the true shape of the particles is once discovered, we obtain with it all the properties which belong to such a shape. I hope that this rests on a solid foundation. In future I should not wish to publish anything which has not better ground to rest upon than the former things in the Dædalus."
In the summer of the same year by the King's command he was engaged in the construction of the above-mentioned Baltic and North Sea
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