The object of the invention which we herewith illustrate, is to enable the spindles of millstones to be adjusted with perfect accuracy, and at the same time to furnish bearings of anti-friction material, which may be kept constantly and perfectly lubricated, and from which all extraneous dust or grit calculated to aggravate friction may be kept excluded. Fig. 1 is a perspective view of this improvement, and Pig. 3 is a sectional view of the same, showing details of con-1 struction. A, Fig. 3, is the spindle, playing in segmental bearings, B. There are four of these which, together, make up the entire bearing for the spindle. They are hollow, as shown in the engraving, and faced with anti-attrition surfaces. The outer sides of these segments are inclined, these surfaces resting against the inclined inner surfaces of the hollow binding wedges, C. Through the lower part of these wedges pass hooked bolts, D, with thumb-nuts at their lower ends, by turning which, the wedges areforced upward,and the segments, B, being prevented from rising by the top plate, E, ai'e forced inward till their surfaces are brought in proper proximity to the spindle. It is evident that by raising and lowering these wedges as circumstances require the spindle can be adjusted with the greatest accuracy. Lubrication is secured by placing a store of oil in the chambers, F, of the segmental bearings, B,f rom Avhloh it is fed, as wanted, through the apertures, G, to the bearing surfaces of the spindle and bush. Lastly, the exclusion of dust and grit is secured by forming a chamber, H, upon the top plate of the bush, with an annular cap which shuts down over it and incloses the spindle, in which chamber is placed packing yarn or other suitable material to intercept all extraneous materials of this character. The top plate is bolted down to the external [portion of the bush, and the whole inclosed as shown in Fig. 1. All experienced millers are aware that the attainment of the above objects by a simple device is a very desirable achievement. By the use of this improvement the adjustment can be readily and accurately made, and the wear of the spindle would seem to be reduced to a minimum. This improvement was patented through the Scientific American Patent Agency.Dec. 31,1867, by C. Custei. For further information address C. K. Bullock, 1,138 Market street, Philadelphia, Pa. RULE 1ST. TO find elasticity of a given steel-plate spring : Breadth of plate in inches multiplied by cube of the thickness in 1-lG inch, and by number of plates ; divide cube of span in inches by product so found, and multiply by 1-G6. Result, equal elasticity in l-16th of an inch per tun of load. RULE SD. TO find span due to a given elasticity, and number and size of plate : Multiply elasticity in sixteenths per tun, by breadth of plate in inches, and divide by cube of the thickness in inches, and by the number of plates; divide by 166, and find cube root of the quotient. Result, equal span in inches. RULE 3D. To find number of plates due to a given elasticity, span, and size of plates : Multiply the cube of the span in inches by 1-66 ; multiply the elasticity in sixteenths by the breadth of the plate in inches, and by the cube of the thickness in sixteenths ; divide the former product by the latter. The quotient is the number of plates. RULE 4TH. To find working strensth of a given steel plate spring : Multiply the breadth of plate in inches by the \ square of the thickness in sixteenths, and by the number of plates ; mu tiply also the working span in inches by 11'3 ; divide the former product by the latter. Eesult, equal working strength in tuns burden. | RULE STH. To find span due to a given strength and number, and size of plate : Multiply the breadth of plate in inches by the square of the thickness in sixteenths, and by the number of plates ; multiply, also, the strengtli in tuns by ; 11-3, divide the former product by the latter. Eesult, equal working span in inches. EuLE 6TH. TO find the number of plates due to a given strength, span, and size of plate : Multiply the strength in tuns by span in inches, and divide by 11-3 ; multiply also the breadth of plate in incliea by the square of the thickness in sixteenths ; divide the former product by the latter. Eesult, equal number of plates. Tlie span is that due to the form of the spring loaded. Extra thick plates must be replaced by an equivalent number of plates of the ruling thickness, before applying the rule. To find this, multiply the number oi extra plates by the square of their thickness, and divide by the gcinaro of the ruling thickness ; conversely, the number of plates of the ruling tliickness to be removed for a given number of extra | plates, may be found in the same way.