How the Illustrations in "Progress" are Produced.

Progress, Volume I, Issue II, 1 September 1906, Page 320

How the Illustrations in " Progress " are Produced.

It is probable that most of our readers know that " half-tone printing blocks," such as are used for illustrating Progress, are produced by photography through the medium of a " screen," which consists of two glass plates joined together and divided by a large number of diagonal lines ruled upon the surfaces. The very interesting enlargement serves to demonstrate how by means of the " screen" the engraver translates the tones of an original — wash drafvving or photograph, for instance — into isolated surfaces suitable for printing purposes When completed the whole surface thus prepared is composed of dots of varying sizes. In the parts corresponding to the high lights of the original the dots are relatively very minute, so that to a given area the amount of mk-bearmg surface is very small, and, consequently, when the ink is transferred to paper the tone of the paper is only slightly darkened. The amount of ink-bearing surface to a given area gradually increases as the scale of tones is descended until the dots run together into beaded lines, and finally an absolute black is produced It is difficult for the ordinary reader to grasp either the need for or the action of the screen which is used in the making of half-tone blocks. Our

Messrs. William Ross & Sons, Ltd., a company formed in Foxton recently, have erected a large rope manufactory. Rope and cordage of all kinds and binder twine are the chief products ; the new factory being in the heart of the flaxmillmg district, is well supplied with the necessary material. The machinery is driven by an 80 h p Campbell gas engine and producer plant ; there being two engines one of 30 h.p. and the other an old engine converted to use suction gas. Messrs. Ross & Sons inform us that a very large saving in power cost is being effected by the use of suction gas. H» *f * *p * *t* The Petter oil engine was first introduced in 1896, since which time nearly 3,000 engines have been made and sold. The actual work of these engines in daily use has won for them an acknowledged reputation for simplicity, workmanship and careful selection of material. The simplicity of the Petter engine lies in the fact that the numerous valves levers, pumps and other complications found in most oil engines are absent. It is, we understand easily looked after and kept in order by an ordinary farm hand, groom, gardener or other person, without previous experience or mechanical knowledge. This engine burns paraffin or kerosene, and the Petter system of governing provides for the exact proportions of oil and air to be maintained, whatever the load on the engine may be There is also patent automatic tube ignition which overcomes most objections by the utilisation of the waste gases of the engine for heating the ignition tube. The highest class

unique instance will assist to demonstrate this. It is an enlargement by projection from an ordinary medium-grained half-tone negative, and is about ten lines to the inch. An examination of it will show that in light parts theie is a small black dot on a white ground, the dot gradually increasing in size as tone deepens until at last in the shadows the back-ground becomes black with a white dot. It is by this alternation from white to black dots and the gradations between these extremes that the photographic effect is retained. In order to obtain the effect of a fine screen the reader should place our illustration about fifteen feet away from the eye. Thus it will be gathered that it is really mechanical in its working principle. According to the kind of screen used so the number of isolated surfaces varies in amount to the same area.

It is currently reported that a paper mill is to be started m Foxton. ****** The flax industry appears to be proceeding upon a sound footing just now, as there is not only a steady demand, but the trade which used to be conspicuous for the fluctuating nature of its course is now settling down into a regular and lucrative industry. One of the most convincing evidences of this fact is that one miller in a large way in the Manawatu district recently sold his output for five years, at per ton.

of workmanship and material only are used in the manufacture of Petter oil engines, the various parts are all made to standard gauges and can be easily renewed when required. The N.Z. agents for these engines are Messrs. L. C. Knight & Co., Hereford street, Christchurch. ****** The Palmers ton North Fresh Food & Cooling Stores, Ltd., are erecting extensive premises on the corner of Church and Princess streets, Palmerston North. The Company propose to deal with fresh food of all descriptions, and provide cold storage for the general public , they will also be buyers of dairy produce, etc. An extensive plant for milking and handling farmers' dairy butter will also be erected and the whole business will be in the hands of a competent manager. An " Atlas " refrigerator will be used. The Company also propose to deal with milk which will be supplied from a picked herd, carefully pasteurised, purified and supplied to customers in carefully sealed bottles. In the same premises the " Perfect " Dairy Machinery Co. will have their show room, where the excellent qualities of the " Perfect " separators can be seen at any time. We wish the Company every success in their new venture, which will supply a long-felt want in the rapidly growing town of Palmerston North. Mr Chas. Dahl is the managing director of the Company, and Mr. L. C. West was the architect of the premises.