Dr. B.P. Saraf, J.- The writ petitioner Sailesh Chandra Nandi, proprietor of a business run under the name and style of "Nandi & Nandi' at Agartala in West Tripura, has filed these two writ pet­itions challenging the orders of assessments passed by the Superin­tendents of Taxes, Agartala for the years ending 31.3.78 and 31.379. The grievance of the petitioner relates to levy of tax on the value of goods supplied in execution of a contract. The case of the pet­itioner is that the contract executed by the petitioner was an indi­visible works contract and not a contract of sale and, as such, no tax could be levied on the value of the materials used in execution of the said contract. This submission did not find favour of the Superintendent of Taxes who was of the opinion that the petitioner was liable to pay tax on the value of materials used in execution of the contract as the same were purchased by the petitioner at a concessional rate by issuing 'C' Form. The assessments were confirmed on appeal by the Assistant Commissioner of Taxes. The Assistant Commissioner also held that disposal of taxable materials brought by using 'C' forms have to be considered as sale and tax levied thereon. The appeals were accordingly rejected. Further appeal was pref­erred before the Tripura Sales Tax Tribunal. The Tribunal considered the dispute from a different angle. It considered as to whether the contract in question was an indivisible works contract or a composite contract for work and sale of goods. On consideration of the terms of the contract, it came to a finding that it was a contract of sale and the job work thereunder, namely, erection and installation was only incidental to the contract of sale. It did not decide the correctness of the stand taken by the Superintendent of Taxes and the Assistant Commissioner of Taxes that as the goods in question were purch­ased on payment of sales tax at concessional rate by issuing 'C"' forms under the Central Sales Tax Act, there was implied sale of such goods. The petitioner has challenged the aforesaid order of the Tribunal on the ground that the Tribunal was not justified in arriving at the aforesaid finding. According to the petitioner the contract in question was an indivisible works contract and the supply of materials was only incidental. The petitioner has challenged the aforesaid order of the Tribunal on the ground that the Tribunal was not justified in arriving at the aforesaid finding. According to the petitioner the contract in question was an indivisible works contract and the supply of materials was only incidental. As such, there was no sale of materials used in the execution of the said works contract which could be subjected to Sales Tax. The further contention of the petitioner is that no sale can be implied from the fact that the goods in ques­tion were purchased on payment of tax at concessional rate by issue of declaration in form 'C' to the effect that such goods were inte­nded for sale. 2. I have heard Mr. B. Das, learned counsel for the petitioner. Also heard Mr. M. Nath, learned counsel for the respondent. Two questions arise for consideration. First, whether any tax can be levied under the Tripura Sales Tax Act, hereinafter 'the Act', on a dealer on the value of goods used by him in a works contract on the ground that the same were purchased at a concessional rate of tax on the strength of 'C' Forms issued under the Central Sales Tax Act. The second is whether the contract in question between the petitioner and the Tripura Jute Mills Ltd. was a pure works contract or a composite contract consisting of two contracts -one for sale of materials and the other for work and labour. 3. So far as the first question is concerned, we find that it is squarely covered by a decision of this Court in M/s. Studio Sen & Sen v. The State of Tripura and others, (1989) 2 GLR 392. The question for determination in that case was whether Sales Tax can be levied on a supposed sale of materials used in execution of an indivisible works contract. The petitioner was a photographer. Some materials were purchased by him at concessional rate by issuing 'C' forms. Such materials were used in preparation of photographs. The admitted legal position was that there was neither any sale of the materials used in the preparation of the photographs nor of the photographs themselves. The petitioner was a photographer. Some materials were purchased by him at concessional rate by issuing 'C' forms. Such materials were used in preparation of photographs. The admitted legal position was that there was neither any sale of the materials used in the preparation of the photographs nor of the photographs themselves. The Sales Tax authorities, however, levied tax on the estimated sale value of materials used in the preparation off the photographs by assuming that the goods imported at concess­ional rate of tax for re-sale had been disposed by the petitioner by way of sale transaction. This Court held (page 397 of the report) : "................In the instant case, admittedly there being no sale of any goods whatsoever, the assessing officer had no authority to levy any tax on the 'assumed sale' of the mat­erials purchased by the petitioner and used in works contract. Such an assumption is not warranted in a taxing statute. If, according to the Assessing Officer, the goods purchased on the strength of 'C' form issued under the Central Sales Tax Act were not used for the purposes for which they were purchased, he could have taken any action against the dealer for such misuse as might be permissible under the said Act. There is a specific provision in sections 10 (b) of the Central Sales Tax Act to deal with such a situation. But that cannot be a ground for levying tax under Tripura Sales Tax Act without there being a sale of such goods in the State of Tripura. In view of what is stated above, we are of the opinion that no tax can be levied under the Tripura Sales Tax Act in res­pect of materials used by the petitioner as a photographer in the works contract undertaken by him as there is no 'sale' of such materials in Tripura within the meaning of clause (g) of section 2 of the Act........" The first question, therefore, is fully answered by the aforesaid decision. 4. We now turn to the next question, namely, whether the con­tract in question is a works contract or a composite contract for work and sale of materials. For determination of this question we shall have to refer to the contract between the parties and the rel­evant terms and conditions. 5. 4. We now turn to the next question, namely, whether the con­tract in question is a works contract or a composite contract for work and sale of materials. For determination of this question we shall have to refer to the contract between the parties and the rel­evant terms and conditions. 5. The contract in question was a contract for "Supply, Del­ivery, Erection and Commissioning of Lighting System (Indoor & Out­door) along with Sub-Distribution Board for Tripura Jute Mills Lim­ited". The petitioner submitted a tender for the said work. The tender was accepted by Tripura Jute Mills and a letter of intent for the said work was issued in favour of petitioner. The work to be executed by the petitioner under the said tender was as follows : SI. No. Description of Items in brief Value 1. Lighting Panel be Crompton make as per schedule of the tender Rs. 57, 858/- 2. Cables be Nicco/Seimens/Fort Gloster as per schedule 'B' of the tender Rs. 1,62,817/- 3. Fittings be Cromption make as per schedule 'C' of the Tender Rs- 2,62,237/- 4. Erection Charges as per tender for the above item Rs. 1,44,500/- Rs. 6,27,412/- 6. Under the terms of the contract, it was the obligation of the petitioner to furnish all equipments and/or materials prescribed in the contract agreement and to supply and provide all staff, equ­ipments required to install the machines and to supervise the ere­ction to the entire satisfaction of the Tripura Jute Mills Ltd. There was also a warranty for satisfactory supply and erection of the mach­ines/equipments. The relevant clauses of the agreement, namely, clauses (2) and (5), are set out below : "2.00 Obligation of N & N : The N & N agrees to perform faithfully to the best of its abi­lity and properly all the services and to furnish all of the equipments and/or materials described in this Contract Docu­ments and to supply and to provide all staff, equipments requ­ired to install the machines and to supervise erection to the entire satisfaction of TJML/Consultant. The installation of all equipments shall be completed within 4 (four) months and shall be reckoned from the 10th (Tenth) day of signing of agree­ment. The time shall be of essence of the contract. The Con­tractor shall produce necessary electrical licence. The materi­als including sand, gravel stone loose earth rock, etc. The installation of all equipments shall be completed within 4 (four) months and shall be reckoned from the 10th (Tenth) day of signing of agree­ment. The time shall be of essence of the contract. The Con­tractor shall produce necessary electrical licence. The materi­als including sand, gravel stone loose earth rock, etc. dug up or excavated from the said shall exclusively belong to the owner and the contractor shall have no right to claim over the same. N & N shall have to furnish manufacturers certific­ate against the equipment as and when desired by TJML. *** *** *** *** 5.00 Warranty : The N & N agrees to furnish warranty for satisfactory supply and erection of the machines/equipment. Any defects due to improper fitting or workmanship shall be rectified to the sati­sfaction of the TJML engineer/Consultant and Engineer of the suppliers of machines. Any breakages or damages of compo­nents/equipments during handling erection shall be replaced or made good of at the earliest possible date". "N & N" that is, Nandi & Nandi in the aforesaid clauses refers to the petitioner and "TJML" is the abbreviation of Tripura Jute Mills Limited. 7. From the nature of the works, the items of works and the terms and conditions of the contract, it is clear that the contract is for supply, delivery, erection and commissioning of lighting system (indoor and outdoor) along with sub-distribution board. Execution of this contract also involves use of some materials. The essence of the contract is erection and commissioning of the lighting system with sub-distribution board. It is to be erected and installed at the site mentio­ned in the contract. The supply of any material including cables, fittings, etc. required for the purpose of the aforesaid work of erection and installation of lighting system has also to be made by the petitioner. The price stipulated in the contract is inclusive of election and commissioning charges. The erection and commissioning of the lighting system is as much an essential part of the contract as the supply of materials. In fact, the contract is for erection and commissioning of the lighting system etc. Till that is done the con­tract is not complete. The price stipulated in the contract is inclusive of election and commissioning charges. The erection and commissioning of the lighting system is as much an essential part of the contract as the supply of materials. In fact, the contract is for erection and commissioning of the lighting system etc. Till that is done the con­tract is not complete. Though the petitioner has also to supply ligh­ting panels, cables and fittings required for the purpose of the ligh­ting system and while fixing the value of the contract the value of all these materials has been taken into consideration as also the value of erection charges etc., the contract is basically a contract for erection and commissioning of the lighting system. The contract is one and indivisible contract for erection and commissioning of lighting system, etc. The contract is complete when the erection is done and the system is commissioned. These are the salient feat­ures of the contract. The question that has to be decided now is whether under the said circumstances the contract in question can be said to be a works contract or a contract for supply of goods and materials. 8. There are some well recognised tests which have been laid down by the Supreme Court and the various High Courts which aff­ord guidelines for determining as to whether a contract is a works contract or the contract for supply of goods. One of the important tests, as observed by the Supreme Court in Vanguard Rolling Shu­tters & Steel Works vs. Commissioner of Sales Tax. U.P., (1977) 39 STC 372 is to find out whether the contract is primarily a contract for supply of materials at a price agreed to between the parties for the materials so supplied and the work or service rend­ered is incidental to the execution of the contract. If so, the cont­ract is one for sale of materials and the sale proceeds would be exigible to sales tax. On the other hand, where the contract is pri­marily a contract for work and labour and materials are supplied in execution of such contract, there is no contract for sale of mat­erials but it is a works contract. If so, the cont­ract is one for sale of materials and the sale proceeds would be exigible to sales tax. On the other hand, where the contract is pri­marily a contract for work and labour and materials are supplied in execution of such contract, there is no contract for sale of mat­erials but it is a works contract. The circumstances that the mater­ials have no separate identity as a commercial article and it is only by bestowing work and labour upon them, as for example, by affi­xing them to the building incase of window-leaves or wooden doors and windows that they acquire commercial identity, would be prima facie indicative of a works contract. So also where certain materials are not merely supplied but fixed to an immovable property so as to become a permanent fixture and an accretion to the said property the contract prima facie would be a works contract. These are some of the basic tests that are often applied by the Courts to decide whether in a particular case the contract is a works contract or not, 9. We may refer in this connection to the decision of the Su­preme Court in the State of Rajasthan vs. Man Industrial Corpora­tion Limited, (1969) 24 STC 349 . In that case the contract was to prepare window leaves according to specification and to fix them to the building. It was held by the Supreme Court that fixing the window leaves to the building was not incidental or subsidiary to the sale but an essential term of the contract, because the contract became complete only after the windows were fixed as stipulated in the contract. In Vanguard Rolling Shutters & Steelworks vs. Commissioner of Sates Tax U. P. (Supra), the assessee manufactured iron shutters according to specifications given by the customers and fixed the same at their premises. Under the terms of the contract the assessee was required to fabricate the rolling shutters, bring them to the site of the customers and thereafter erect them at the pre­mises. The masonry work had to be done by the customers at their cost according to the assessee's instruction. The assessee was entitled to receive full price of the shutters against delivery and there was no such thing as to make payment after fixing. The masonry work had to be done by the customers at their cost according to the assessee's instruction. The assessee was entitled to receive full price of the shutters against delivery and there was no such thing as to make payment after fixing. The question before the Supreme Court was whether it was a works contract or a contract for supply of goods. The Supreme Court held that the contract in question could not be said to be a pure and simple sale of goods or materials as chattels, but it was works contract. It was observed that the contract could not be completed merely by sending the materials at the site but would be completed only after the erection of the shutters had been made and the shutters fixed to the premises so as to become an accretion to the premises. The Supre­me Court followed its earlier decision in Man Industrial Corpora­tion Ltd. (Supra) and held that the contract was a works contract and the transaction was, therefore not exigible to tax. 10. This decision was followed in Sentinel Rolling Shutters A Engineering Company Pvt. Ltd. vs. The Commissioner of Sales Tax (1978) 42 STC 409 . It was also a case of contract for fabrication, supply, erection and installation of rolling shutters. In this case also, on interpretation of the terms of the contract, it was held that the contract was one single and indivisible contract and the erection and installation of rolling shutters was as much as a funda­mental par of the contract as the fabrication and supply. The contract was- held to be clearly and indisputably a contract for work and labour and not a contract for sale. 11. Reference may also be made to another decision of the Supreme Court in Ram Singh & Sons Engineering Works vs. Commi­ssioner of Sales Tax, U.P. : (1979) 43 STC 195 . In this case question arose as to whether the contract for fabrication and erection of a 3-motion electrical overhead' travelling crane is a contract or work and labour or a contract for sale The Supreme Court, allowing its earlier decisions, held that it was a contract for work and labour and not a contract for sale. In this case question arose as to whether the contract for fabrication and erection of a 3-motion electrical overhead' travelling crane is a contract or work and labour or a contract for sale The Supreme Court, allowing its earlier decisions, held that it was a contract for work and labour and not a contract for sale. It was observed (at page 202) : "....the fabrication and erection of a 3-motion electrical overhead travelling crane is a highly skilled and specialized job and the component parts have to be taken to the site and they are assembled and erected there and it is only when this process is complete than a 3-motion electrical overhead travelling crane conies into being. The process of assembly and erection requires a high degree of skill and it is not possible to say that the erection of a 3-motion electrical overhead travelling crane at a site is merely incidental to its manu­facture and supply The fabrication and erection is one single indivisible process and a 3-motion electrical overhead travelling crane comes into existence only when the erection is complete. The erection is thus a fundamental and integral part of the contract, because without it the 3-motion electrical overhead travelling crane does not come into being. The manufacturer would undoubtedly be the owner of the component parts wheat he fabricated them, but at no stage does he become the owner of the 3-motion electrical overhead travelling crane as a unit so as to transfer the property in it to the customer. The 3-motion electrical overhead travelling crane comes into existence as a unit only when the component parts are fixed in position and erected at the site, but at that stage it becomes the property of the customer because it is permanently embedded in the land belonging to the customer. The result is that as soon as 3-motion electrical overhead travelling crane comes into being, it is the property of the customer and there is, therefore, no transfer of property in it by the manufacturer to the customer as a chattel. It is essentially a transaction for fabricating component parts and putting them together and erecting them at the site so as to constitute a 3-motioa electrical overhead travelling crane. The transaction is no different than one for fabrication and erection of an open godown or shed with asbestos or tin sheets fixed on columns. It is essentially a transaction for fabricating component parts and putting them together and erecting them at the site so as to constitute a 3-motioa electrical overhead travelling crane. The transaction is no different than one for fabrication and erection of an open godown or shed with asbestos or tin sheets fixed on columns. There can, therefore, be no doubt that the contract in the present case was a contract for work and labour and not a contract for sale......". 12. In Hindustan Aeronautics Ltd. vs. State of Karnataka, (1984) 55 STC 314 (SC), at page 322, it was observed : " ... Mere passing of property in an article or commodity during the course of performance of the transaction in ques­tion does not reader the transaction to be transaction of sale. Even in a contract purely of work or service, it is possible that articles may have to be used by the person executing the work, and property in such articles or materials may pass to the other party. That would not necessarily convert the contract into one of sale of those materials. In every case, the Court would have to find out what was the primary object of the transaction and the intention of the parties while entering into it ....'' 13. In the aforesaid case a dispute arose as to whether supply of spare parts and materials by the appellant in execution of works contract amounted to sale. On consideration of the terms and conditions of the contract, it was held that there was no sale thereof and their turnover was not exigible to sales tax. 14. Considering the facts of the present case in the light of the decisions set out above, it is evident that the contract in the present case was a contract for work and labour and not a contract for sale. The erection and commissioning of the lighting system was the fundamental and integral part of the contract. It is essentially a transaction for erection and commissioning of the lighting system. The contract is complete only when the system is commissioned. The supply of materials is merly ancillary to the said contract. The contract was, therefore, a contract for work and not a contract for sale. It was, therefore, not exigible to sales tax. It is essentially a transaction for erection and commissioning of the lighting system. The contract is complete only when the system is commissioned. The supply of materials is merly ancillary to the said contract. The contract was, therefore, a contract for work and not a contract for sale. It was, therefore, not exigible to sales tax. The Sales Tax authorities and the Tribunal were in error in holding that the petitioner was liable to pay tax on the value of materials used in execution of the said contract. 15. We, therefore, allow these writ petitions, set aside the Impugned orders of assessments and direct the Superintendent of Taxes to re-assess the turnover of the petitioner after excluding the value of the goods used in execution of the contract aforesaid. We make no order as to cost. I agree,