March 29, 1889.] 



SCIENCE. 



2M 



Hill Observatory, the United States Signal Office, Harvard College 

 Observatory, the Institute of Technology, the Boston Water Works, 

 and the Draper Manufacturing Company of New York. Owing to 

 the generous response to the circular requesting the loan of articles, 

 particularly by the United States Signal Service, the exhibition was 

 a success, and was so well attended by visitors that it was con- 

 tinued three days longer than was originally intended. Now that 

 the feasibility of such an exhibition has been demonstrated, it is to 

 be hoped that others will follow, as there can be no doubt of their 

 effect in stimulating the study of meteorology. 



THE HORNIG DIRECT-POWER STEERING SYSTEM. 



The steering system herewith illustrated is the invention of Ju- 

 lius L. Hornig of Jersey City, N.J. It may be operated by steam, 

 hydraulic, or pneumatic pressure, the last being preferable. The 

 motor is attached directly to the rudder-head, as shown in the 



not being removed, so that the vessel may be steered by hand if 

 necessary. In fact, either hand or power steering may be done, or 

 both at once, as neither system interferes with the other. / and A' 

 are guide-pulleys for the usual tiller-ropes, i?, R are relief-cocks, 

 and P is a. regulator-cock for the brake. 



The motor has three pistons, working in an annular chamber, as 

 shown in Figs. 3 and 4. A and C are the bottom and top cases of 

 the chamber ; B, the pistons ; D, the legs by which the motor is 

 secured to the deck ; £; the ports ; //, the valve-chest ; /, the in- 

 let-pipe ; and K, the outlet-pipe. Af is a lever for working the 

 regulator- valve U, and jVis the main valve-lever. 5 is the rudder- 

 head ; T, the motor hub ; and F", the end covers or abutments. 



The reason for preferring pneumatic pressure to operate the 

 motor is that liquids have practically no elasticity, and may freeze, 

 while steam will condense. Air, on the other hand, is subject to 

 no change ; and its elasticity makes it an excellent cushion to re- 

 ceive the shocks of wave-blows, thus relieving the mechanism from 

 sudden strain. In 1886 two boards of naval experts, acting under 

 government instructions, made trials of pneumatic steering-gear, 

 and reported its superiority over other methods. 



The pressure-valve, which is operated by the lever, as shown in 

 the cut, regulates the action of the pistons by supplying pressure to 

 one side while relieving that on the other, or vice versa ; while the 

 pistons and rudder will remain stationary when the valve is kept 

 closed. The motor may be controlled from any part of the vessel 

 by any of the usual mechanical methods or by electrical transmis- 

 sion. 



illustrations, though a special form of the motor is made which 

 may be placed in any convenient part of the vessel, connecting 

 with the rudder by chains, ropes, or rods. 



The motor is shown at M in Figs, i and 2, the usual tiller, L, 



Professors Ayrton and Perry announce that Messrs. J. W. 

 Queen & Co. of Philadelphia, Penn., are alone authorized to sell 

 their electrical measuring instruments in the United States and in 

 Mexico, and all instruments sent to America which have satisfac- 

 torily passed their tests will bear the firm's name on them as 

 American agents, as well as being accompanied by a certificate of 

 accuracy. 



