"I wish only to say that these lessons have led me to such thoughts of God's wisdom and goodness as I never had before. Of course it is not strange that this should be the case with me. I now look at everything with new eyes. It is not merely this one element of heat in Nature that moves my admiration, but I have been led to consider a thousand things in which the goodness of God is shown. My thoughts of the divine goodness are as fresh and interesting to me as my impressions of his righteousness and holiness are startling. For years I have tried with might and main to look upon the dark side of the world and to exaggerate its physical evils. I have searched for disorder and want of adaptation. As long as I misunderstood the purpose of the creation, I thought I was successful in impugning the wisdom of the arrangements of this physical world. While I supposed that the earth must needs be the Creator's masterpiece in beauty and pleasantness and all manner of perfections, designed just to give sensual pleasure to its inhabitants, I could find, or thought I found, many faults in the Creator's work. Now I withdraw all my former charges. My eyes are opened. The rougher elements of man's life will henceforth have a new meaning to me. I see that God seeks not so much present pleasure for men as their holiness. He lays a solid foundation for their happiness. He seeks to render men blessed by bringing them into likeness and union with himself. These are new views to me, and I thank my heavenly Father that this new light has dawned upon me. I feel now that I can bear the ills of this life cheerfully, understanding that the Lord is using them as a means of spiritual discipline. It seems to me as if this lower world and man's lowly life were already glorified by a beam of light falling from heaven. I hope that my young friends have been as much profited as I have been." "I rejoice with you, Mr. Hume. 'We know that all things work together for good to them that love God.' This light has shone upon me for many years." CHAPTER XV. ECONOMY OF HEAT. "In this final lesson I wish," said Mr. Wilton, "to bring before you some general views of the whole subject of the agency and management of heat.