Many who have wondered at the name of Portland cement will be interested to know that it originated in Leeds, England. A bricklayer named Joseph Aspdin patented an artificial cement in 1824 and called it "Portland Cement," owing to its resemblance to the famous building stone then quarried at Portland, England. As then made, it was a lightly colored mixture of lime and clay, which was afterwards ground. He started a factory for making it at Wakefield in 1825, and some of the cement was used in the Thames Tunnel by Sir I. K. Brunei, the famous engineer, in 1828 •
It is commonly believed by non-technical persons that anything called "steel" must necessarily be stronger than iron. As a matter of fact, poor steel is miserable stuff, not to be compared with decent wrought iron, though the latter is a scarce material nowadays.
"Our local newspaper had its lynx eye on a smoky chimney that belonged to an ex-mayor of the town. It held that public men should not be producers of public nuisances.
I called to see my friend, the ex-mayor, and he said, 4 Look, here, they are at it again and now they threatening prosecution.' He told me what he had done to prevent smoke pollution. He had put in patent stokers, steam jets to aid the draft, a new sort of patent grate bars, raised the chimney 25 ft. and had used a better class of coal, and he said 'What more can I do?' He was a busy man and was glad when 1 offered to go to his works to see if I could suggest anything that could be done.
So much depends on the fireman that we came to the conclusion that it must be all his fault. I found, however, that the two boilers which had been quite sufficient for the works as originally planned were not so now a large dye house had been added and was in full blast.
I suggested that a 32-inch Sturtevant fan be put in at the root of the chimney - this fan to work at a varying speed to suit the demand for steam. A fan was put in and it ended the trouble, no more complaints about black smoke, plenty of steam for all purposes, the quantity and quality of the work was improved, and all at a comparatively small cost, which was soon repaid by less coal consumption."-"Engineer"
In casting the soft metal in plaster molds, it has been found that a very much thinner casting may be made if melted wax is allowed so soak into the plaster after it has been dried. The method of using this is to make the mold in the usual manner and then allow some wax to melt and permeate the mold. This can be done after it has been removed from the drying oven. This method causes the metal to flow with great fluidity, and every part of the mold will be permeated; therefore a much thinner casting than otherwise may be cast. Japan wax is what is used, as this answers the purpose and is a cheap form of wax. This method is now being used in one of the largest hollow-ware concerns with excellent results.