If it were not that another American, a cycle-maker, has apparently made a success of a roller-clutch, I should be tempted to warn all experimenters against it as a thing that “stingeth like a serpent and biteth like an adder.” [Illustration: Loose centre roller-clutch.] Under a bench in a shop not far from the geographical centre of England may still be found about a bushel of friction-clutches of various and ingenious forms, which future historians in the art will find very interesting. Should any one wish to enter the arena as a searcher for the true friction-clutch, let him first examine these specimens, and he will start several years ahead. The nearest approach to a success which the writer has fallen upon is illustrated below for the purpose of helping those who may wish to carry on the search, or experiment in clutch-cycles,—if any should think it worth while in view of the alleged success of the American above referred to. The clutch illustrated below was contrived by a fellow-laborer in the field. The drawing represents the device in a crude form; some improvements having been necessary to complete it. _B_ is a cog-wheel within another, _A_, the latter fast to the wheel-hub, and the former to the clutch-drum. A wedge, _E_, follows between the wheels, whence it will be seen that they can revolve, in relation to each other, in one direction only. [Illustration: Scott wedge-clutch.] For those who wish to study this question more minutely, Kempe, on link motion, will be found a valuable work in connection with the construction of levers in any art, when it is desired to obtain a motion in a straight line from an oscillating or circular. In the way of conclusion, reverting to the possibilities of direct application of these remarks to the actual purchase and use of cycles, I wish to say, in regard to the mechanical difficulties in this matter of lever and clutch machines, that so long as the use of oil is necessary, I have very grave doubts if a thoroughly satisfactory, noiseless friction-clutch for use on cycles will ever be invented. TANGENT VS. DIRECT SPOKES. [Illustration: Tangent spokes.]