In the engraving of the bevel core wheel is shown (to the right of it) a wood cog as we furnish them from the machine. The now extensive demand, built up by close attention to this small but very important branch, for now over fifteen years, has made it necessary to prepare ourselves by keeping a larger stock of the material as well as improved machinery for making them. At the proper time each year we have cut of hickory, sugar, (often termed maple,) and some oak specially for this purpose, and we have at no time less than 25,000 feet of the best lumber, part of it being from three to six years old. For this purpose we use only the butt logs cut from trees standing exposed in the out-skirts of the timber. When cogs are wanted to refill a wheel it is best to take out one of the old ones and fit a temporary one in place of it, then send to us by express, with your order by mail, or with the cog, of the number wanted. The cogs will be shanked and place cut for the keys exactly as per sample, _and all uniform_, unless otherwise ordered. It is desirable for us to know about what the pitch of the gear is, although the projecting part of the cog is left of ample size to shape the tooth. We always box them, and ship by freight or express, as ordered. It is no uncommon thing for us to send cogs thus over a thousand miles from our works. SPUR GEARED MILLS Are furnished to order to be driven by spur or crown wheel gear, direct from upright shaft, in iron or wood husks, or without husks as preferred. Such a mill is constructed to drive one or half a dozen run of stones from one crown wheel. The iron pinions are made to lift from suitable iron sleeves when necessary to stop one or more of the stones. This device is simple and not objectionable. To those who prefer to make the husks at the mill house we will send drafts and description showing how every part, iron and piece is located, as well as the entire structure on the most approved plan. Management of Water Power. Here is where bad mistakes are often made, and the best of water wheels sometimes condemned when the fault may be in not properly attaching the wheel, or improper application of the water, or speed or size of wheel not properly proportioned to the height of head or amount of water. And we ask of parties interested in water powers to apply to us for advice, should they have no one at hand competent to counsel with. We have furnished and put in many kinds of water wheels for flouring mill purposes, and carefully observed the workings of them, some of which are still prominently before the public, and our experiences have developed some valuable points of interest to those building water mills. Measurement of Water in a Stream. [Illustration]