THE SCIENCE OF CLAY-WORKING. 463 



In connection with this I wish to make a proposition to the tile and brick 

 makers. If each one of you will mold and burn for me a number of prisms 

 of your clay four inches long and one inch square, I will test those prisms for 

 strength and durability and let you know the results. If you will burn these 

 in different portions of your kiln these results will be valuable as giving the 

 effects of heat. 



Composition of pure clays: Silica, 46.3; alumina, 39.8; water, 13 9. 

 Silica is composed of silicon, 1 part; oxygen, 2 parts. Alumina is com- 

 posed of aluminum, 2 parts; oxygen, 3 parts. 



ARRANGEMENT OF MACHINERY AND KILNS. 



This is no doubt a very important matter, and there is probably no busi- 

 ness in which it is of greater importance, from the fact that the manufacture 

 of brick or tiles as usually conducted is largely done with hand labor. Any 

 arrangement which can save steps of a laborer will reduce the cost of manu- 

 facture. 



There is probably no business in which the arrangement of machinery is 

 so dependent on circumstances as in clay working. The probability is that 

 the clay or material will be' in such a position, with respect to the conforma- 

 tion of the yard, as to make it impossible to secure the arrangement desired. 

 Again, mistakes are oftentimes made in laying out the work for the various 

 men in the yard. Some positions may require more men and others less than 

 was originally supposed. This fact will make it necessary to make changes 

 or additions in what might otherwise have been a perfect plan. 



Again, the clay itself may work very differently from what was expected, 

 with the result to make the buildings and arrangement essentially bad. This 

 will be seen after a few years by changes made in the plant. If costly build- 

 ings are put up in the first instance, unsightly additions are soon added. 



The theory of perfect arrangement is simple in the extreme and no doubt 

 is fully understood by all. The prime object is to so arrange the machinery 

 as to require the least possible expenditure of force in carrying the clay 

 through the various processes of manufacture, and until stored for the 

 market. This of course requires short distances and no doubling or turning 

 on the track. When engines are used to do the hauling, distances are of less 

 account than sudden bends. 



The arrangement of the Fire Clay Works at Jackson, Mich., is a stu^lied 

 one and probably as good as could be devised for the system of manufacture 

 used, in that the predominant or ruling feature of the arrangement is the 

 factory. This is of rectangular form, three stories in height ; clay is drawn 

 into one end, the tile are dried in the building and sent out in the other 

 three directions to the various kilns. The other features of the arrangement, 

 while as good as circumstances will admit, are certainly not ideal. The stor- 

 ing yard is not conveniently connected with the kilns. 



No doubt more could be said on the method of arranging kilns and plant, 

 but after all, peculiar circumstances in each particular case will prove stronger 

 than principle or theory. 



CLAY WORKING MACHINERY. 



It has been stated by an eminent member of this association that '' despite 

 the intricate and automatic]machinery built by many during the past few years. 



