Motion Picture News (Jul - Sep 1926)

166 .1/ o t i o n P i dure News Projection ty,Praetical Ideas ^ a^|el Inquiries and Comments Carbons Break Condensers ETER BYLSMA, who operates the Victory Theatre, Napoleonville, La., is having trouble with condenser lenses and attributes it to a new carbon which, he says, the National Carbon Company has placed on the market. His complaint reads as follows: — "Dear Sir: Ever since we began using the new carbon the National Carbon Company is putting out, our condenser lenses have been breaking. Prior to this, we had been using the same lenses four and one half years without any trouble at all, but the first night we used the new ones both lenses, 1 mean the rear lens in both pro lectors, cracked so badly that I was obliged to write to the Monarch Theatre Supply Co., Memphis, for two new ones. These immediately followed suit so I ordered two more and asked them for advice in the matter atid they suggested the Pyrex lens as the one that would not only resist breakage but -would give excellent results. We have two Motiograph projectors, \o. 1 — A, 1916 Model and we use alternating current. 1 ordered some :,s in. A. C. Special White in place of the -''4 in. we have always used in the hope that this size might not be so severe on the lenses. I also installed a 12 in. oscillating fan just above and between the two lamp houses ill the hope that, by driving out the hot air, we' might relieve them somewhat. This seemed to do the work because we had no trouble last night. I am inclosing a self-addressed stamped envelope so you can tell me if the Pyrex lens is really good in every wax." A New Carlton? Concerning this matter of the new carbon, Friend Bylsma, we must confess that you have us guessing there. We have heard of no new development in carbons other than the positive electrode developed for the high intensity lamp and yon are not using such a device. There is very little, indeed, in your letter to give us a clue as to \\ hat can be causing your I rouble ot her I ban the fact that immediately after switching to this new carbon you speak of, the collector lenses in both projectors began to break. \ recommendation on our part would, alter all, be in the nature of a guess and in the hope that the National Carbon Com pany are better guessetrs than we. a copy our letter is being enl tot hem with the request that they explain, if possible, the ■ of your t rouble. A comfortable corner of one of the rest rooms in Maurice Baum's new Cathaum Theatre, opened a few weeks ago at State College, Pa. We are assuming, of course, that your trouble lies in the matter of the carbons you are using and if this is so, then the National people are better qualified than we to give an expert opinion. Pyrex Condensers In the matter of Pyrex condensers, we can >ay definitely that such glass will stand up under high temperature without cracking or breaking because that is the principal thing for which it was designed. It seems to us, however, that it should be unnecessary for you to resort to the use of Pyrex in connection with an A. C. are providing the other conditions, as for instance, proper lamp house ventilation, are satisfactory. Neither does it seem probable that the National Carbon Company would know ingly place on the market a carbon which woidd result in such frequent breakage of condensers. With large companies, you are fairly certain of the behavior of their products before they are ever placed on the market for general use. However, we will see what reply they make to your forwarded letter. Pyrex glass condensers, while especially built for heat resisting work, have no disadvantages, optically, as compared with the standard lenses. When they lirst appeared in the form of prismatic condensers for use with Ma/da, the glass had a decidedly greenish tinge but we believe that has now been corrected and a clear white glass is being provided. It also sticks in our mind that the light loss with this glass is somewhat higher than with the regular condenser lenses but it 1not enough to warrant serious considera I loll. If it is found that your trouble really lies in the kind of carbons being used then Pyrex will probably be the solution. Hi {ih Intensity Carbon Saver Because of the peculiar construction of High Intensity lamps it wa found necessary to discard the positive carbons when they were burned down to a length of about six or seven inches. As this represents about one-third of the total length of the electrode it is obvious that a serious waste occurs. It is rather poor economy to buy high-priced carbons and then have to throw away one-third of them. Many attempts, some quite ingenious, have been made to eliminate this wasteful condition, but it appears that none ever amounted to much until the appearance of a recent invention, which makes it possible to burn carbons with convenience and safety, down to a length of one inch. This device consists of two parts: — a grinder and an adapter. The former is used to grind a shoulder on the back, or flat end of the stub. This is then placed in the adapter and the two are ready for insertion in the lamp in the same manner as the original carbon, the adapter acting as an extension of the carbon stub. The adapter, into which the shoulder of the ground carbon stub fits, is a piece of heat resisting steel tube which is split longitudinally for about two inches at the end which receives the carbon stub. A countersunk screw is used to make the ends of the tube grip the shoulder of the stub (irmly. The outside diameter of the adapter is the same as that of the original carbon: 13.6 m.m. of 11 m.m., wheil the inside diameter is the same as that of the shoulder which is ground on the stub. A ring, or collar, mi the L3.6 m.m., or a set pin on the 11 m.m., adapter prevents it from feeding too far forward and coming in contact with the flame. The grinder is so constructed that one end of it tit on to the crankshaft of the projector mechanism so that it revolves when the machine is running. It can be attached and detached in the sam< way as the crank-handle. The other end of the grinder has a guide-hole into which the carbon to be ground is inserted. Inside this guide-hole is a blade which grinds off a thin shoulder when the carbon stub is pressed gently inward. This part of the grinder is provided with a removable dust cover which catches the dust from the carbon and prevents it from getting on the machine or on the floor. This device is manufactured and Mild by the W. & W. Specialty Mfg. Co. It is claimed that local theatres are already using it. Wurlitzer Installed at Loew's Regent Loew's Etegenl Theatre. Harrisburg, has just completed the installation of a new Wurlit/.er Hope-.lones organ ol' the most modern type.